History of Paris

Between 250 and 225 BCE, during the Iron Age, the Parisii, a sub-tribe of the Celtic Senones, settled on the banks of the Seine. At the beginning of the 2nd century BCE, they built an oppidum, a walled fort, whose location is disputed. It may have been on the Île de la Cité, where bridges of an important trading route crossed the Seine.

In his account of the Gallic wars, Julius Caesar addresses an assembly of leaders of the Gauls in Lucotecia, asking for their support. Wary of the Romans, the Parisii listened politely to Caesar, offered to provide some cavalry, but formed a secret alliance with the other Gallic tribes, under the leadership of Vercingetorix, and launched an uprising against the Romans in January 52 BCE.

One year later, the Parisii are defeated by the Roman general Titus Labienus at the Battle of Lutetia. A Gallo-Roman garrison town, called Lutetia, is founded on the left bank of the Seine. The Romans built an entirely new city as a base for their soldiers and the Gallic auxiliaries intended to keep an eye on the rebellious province. The new city was called Lutetia or "Lutetia Parisiorum" ("Lutèce of the Parisii"). The name probably came from the Latin word luta, meaning mud or swamp Caesar had described the great marsh, or marais, along the right bank of the Seine. The major part of the city was on the left bank of the Seine, which was higher and less prone to flood. It was laid out following the traditional Roman town design along a north–south axis.

On the left bank, the main Roman street followed the route of the modern day Rue Saint-Jacques. It crossed the Seine and traversed the Île de la Cité on two wooden bridges: the "Petit Pont" and the "Grand Pont" (today's Pont Notre-Dame). The port of the city, where the boats docked, was located on the island where the parvis of Notre Dame is today. On the right bank, it followed the modern Rue Saint-Martin. On the left bank, the cardo was crossed by a less-important east–west decumanus, today's Rue Cujas, Rue Soufflot and Rue des Écoles.

Christianity was introduced into Paris in the middle of the 3rd century CE. According to tradition, it was brought by Saint Denis, the Bishop of the Parisii, who, along with two others, Rustique and Éleuthère, was arrested by the Roman prefect Fescennius. When he refused to renounce his faith, he was beheaded on Mount Mercury. According to the tradition, Saint Denis picked up his head and carried it to a secret Christian cemetery of Vicus Cattulliacus about six miles away. A different version of the legend says that a devout Christian woman, Catula, came at night to the site of the execution and took his remains to the cemetery. The hill where he was executed, Mount Mercury, later became the Mountain of Martyrs ("Mons Martyrum"), eventually Montmartre. A church was built on the site of the grave of St. Denis, which later became the Basilica of Saint-Denis. By the 4th century, the city had its first recognized bishop, Victorinus (346 CE). By 392 CE, it had a cathedral.

The gradual collapse of the Roman empire due to the increasing Germanic invasions of the 5th century, sent the city into a period of decline. In 451 CE, the city was threatened by the army of Attila the Hun, which had pillaged Treves, Metz and Reims. The Parisians were planning to abandon the city, but they were persuaded to resist by Saint Geneviève (422–502). Attila bypassed Paris and attacked Orléans. In 461, the city was threatened again by the Salian Franks led by Childeric I (436–481). The siege of the city lasted ten years. Once again, Geneviève organized the defense. She rescued the city by bringing wheat to the hungry city from Brie and Champagne on a flotilla of eleven barges.

In 486, Clovis I, King of the Franks, negotiates with Saint Genevieve the submission of Paris to his authority. Burial of Saint Genevieve atop the hill on the left bank which now bears her name. A basilica, the Basilique des Saints Apôtres, is built on the site and consecrated on 24 December 520. It later becomes the site of the Basilica of Saint-Genevieve, which after the French Revolution becomes the Panthéon. She became the patron saint of Paris shortly after her death.

The Franks, a Germanic-speaking tribe, moved into northern Gaul as Roman influence declined. Frankish leaders were influenced by Rome, some even fought with Rome to defeat Atilla the Hun. In 481, the son of Childeric, Clovis I, just sixteen years old, became the new ruler of the Franks. In 486, he defeated the last Roman armies, became the ruler of all of Gaul north of the river Loire and entered Paris. Before an important battle against the Burgundians, he took an oath to convert to Catholicism if he should win.

He won the battle, and was converted to Christianity by his wife Clotilde, and was baptised at Reims in 496. His conversion to Christianity was likely seen as a title only, to improve his political position. He did not reject the pagan gods and their myths and rituals. Clovis helped to drive the Visigoths out of Gaul. He was a king with no fixed capital and no central administration beyond his entourage. By deciding to be interred at Paris, Clovis gave the city symbolic weight. When his grandchildren divided royal power 50 years after his death in 511 , Paris was kept as a joint property and a fixed symbol of the dynasty.

In the 9th century, the city was repeatedly attacked by the Vikings, who sailed up the Seine on great fleets of Viking ships. They demanded a ransom and ravaged the fields. In 857, Björn Ironside almost destroyed the city. In 885–886, they laid a one-year siege to Paris and tried again in 887 and in 889, but were unable to conquer the city, as it was protected by the Seine and the walls of the Île de la Cité. The two bridges, vital to the city, were additionally protected by two massive stone fortresses, the Grand Châtelet on the Right Bank and the "Petit Châtelet" on the Left Bank, built on the initiative of Joscelin, the bishop of Paris. The Grand Châtelet gave its name to the modern Place du Châtelet on the same site.

In the fall of 978, Paris was besieged by the Emperor Otto II during the Franco-German war of 978–980. At the end of the 10th century, a new dynasty of kings, the Capetians, founded by Hugh Capet in 987, came to power. Though they spent little time in the city, they restored the royal palace on the Île de la Cité and built a church where the Sainte-Chapelle stands today. Prosperity returned gradually to the city and the Right Bank began to be populated. On the Left Bank, the Capetians founded an important monastery: the Abbey of Saint-Germain-des-Prés. Its church was rebuilt in the 11th century. The monastery owed its fame to its scholarship and illuminated manuscripts.

The flourishing of religious architecture in Paris was largely the work of Suger, the abbot of Saint-Denis from 1122–1151 and an advisor to Kings Louis VI and Louis VII. He rebuilt the façade of the old Carolingian Basilica of Saint Denis, dividing it into three horizontal levels and three vertical sections to symbolize the Holy Trinity. Then, from 1140 to 1144, he rebuilt the rear of the church with a majestic and dramatic wall of stained glass windows that flooded the church with light. This style, which later was named Gothic, was copied by other Paris churches: the Priory of Saint-Martin-des-Champs, Saint-Pierre de Montmartre, and Saint-Germain-des-Prés, and quickly spread to England and Germany.

In 1150, the future University of Paris was a student-teacher corporation operating as an annex of the Notre-Dame cathedral school. The earliest historical reference to it is found in Matthew Paris' reference to the studies of his own teacher (an abbot of St. Albans) and his acceptance into "the fellowship of the elect Masters" there in about 1170, and it is known that Lotario dei Conti di Segni, the future Pope Innocent III, completed his studies there in 1182 at the age of 21.

The corporation was formally recognised as an "Universitas" in an edict by King Philippe-Auguste in 1200: in it, among other accommodations granted to future students, he allowed the corporation to operate under ecclesiastic law which would be governed by the elders of the Notre-Dame Cathedral school, and assured all those completing courses there that they would be granted a diploma.

The university had four faculties: Arts, Medicine, Law, and Theology. The Faculty of Arts was the lowest in rank, but also the largest, as students had to graduate there in order to be admitted to one of the higher faculties. The students were divided into four nationes according to language or regional origin: France, Normandy, Picardy, and England. The last came to be known as the Alemannian (German) nation. Recruitment to each nation was wider than the names might imply: the English-German nation included students from Scandinavia and Eastern Europe.

The faculty and nation system of the University of Paris (along with that of the University of Bologna) became the model for all later medieval universities. Under the governance of the Church, students wore robes and shaved the tops of their heads in tonsure, to signify they were under the protection of the church. Students followed the rules and laws of the Church and were not subject to the king's laws or courts. This presented problems for the city of Paris, as students ran wild, and its official had to appeal to Church courts for justice. Students were often very young, entering the school at 13 or 14 years of age and staying for six to 12 years.

At the beginning of the 12th century, the French kings of the Capetian dynasty controlled little more than Paris and the surrounding region, but they did their best to build up Paris as the political, economic, religious and cultural capital of France. The distinctive character of the city's districts continued to emerge at this time. The Île de la Cité was the site of the royal palace, and construction of the new Cathedral of Notre-Dame de Paris began in 1163.

The Left Bank (south of the Seine) was the site of the new University of Paris established by the Church and royal court to train scholars in theology, mathematics and law, and the two great monasteries of Paris: the Abbey of Saint-Germain-des-Prés and the Abbey of Saint Geneviève. The Right Bank (north of the Seine) became the centre of commerce and finance, where the port, the central market, workshops and the houses of merchants were located. A league of merchants, the Hanse parisienne, was established and quickly became a powerful force in the city's affairs.

Philip Augustus orders the paving of the major streets of the city with cobblestones (pavés).

At the beginning of the Middle Ages, the royal residence was on the Île de la Cité. Between 1190 and 1202, King Philip II built the massive fortress of the Louvre, which was designed to protect the Right Bank against an English attack from Normandy. The fortified castle was a great rectangle of 72 by 78 metres, with four towers, and surrounded by a moat. In the centre was a circular tower thirty meters high. The foundations can be seen today in the basement of the Louvre Museum.

In 1231, the draining of the marshes Le Marais begins. In 1240, the Knights Templar built a fortified church just outside the walls of Paris, in the northern part of the Marais. The Temple turned this district into an attractive area which became known as the Temple Quarter, and many religious institutions were built nearby: the convents des Blancs-Manteaux, de Sainte-Croix-de-la-Bretonnerie and des Carmes-Billettes, as well as the church of Sainte-Catherine-du-Val-des-Écoliers.

For the first time, the ringing of the bells of the churches of Paris is regulated by clocks, so that all sound at about the same time. The time of day becomes an important feature in regulating the work and life of the city.

Money-changers establish themselves on the Grand Pont, which becomes known as the Pont-au-Change. Several bridges bearing the name Pont au Change have stood on this site. It owes its name to the goldsmiths and money changers who had installed their shops on an earlier version of the bridge in the 12th century. The current bridge was constructed from 1858 to 1860, during the reign of Napoleon III, and bears his imperial insignia.

The Black death, or bubonic plague, ravages Paris. In May 1349, it becomes so severe that the Royal Council flees the city.

Due to the wars of Henry V on France, Paris fell to the English between 1420–1436, even the child king Henry VI was crowned the king of France there in 1431. When the English left Paris in 1436, Charles VII was finally able to return. Many areas of the capital of his kingdom were in ruins, and a hundred thousand of its inhabitants, half the population, had left the city.

After a series of victories, the army of Charles VII surrounds Paris. Charles VII promises amnesty to the Parisians who supported the Burgundians and English. There was an uprising within the city against the English and Burgundians. Charles VII returns to Paris on November 12 1437, but remains only three weeks. He moves his residence and the court to the Châteaux of the Loire Valley. Succeeding monarchs chose to live in the Loire Valley and visited Paris only on special occasions.

The first Cluny hôtel was built after the Cluny order acquired the Ancient thermal baths in 1340. It was built by Pierre de Chaslus. The structure was rebuilt by Jacques d'Amboise, abbot in commendam of Cluny 1485–1510; it combines Gothic and Renaissance elements. The building itself is a rare extant example of the civic architecture of medieval Paris.

By 1500, Paris had regained its former prosperity, and the population reached 250,000. Each new king of France added buildings, bridges and fountains to embellish his capital, most of them in the new Renaissance style imported from Italy.

King Louis XII rarely visited Paris, but he rebuilt the old wooden Pont Notre Dame, which had collapsed on 25 October 1499. The new bridge, opened in 1512, was made of dimension stone, paved with stone, and lined with sixty-eight houses and shops. On 15 July 1533, King Francis I laid the foundation stone for the first Hôtel de Ville, the city hall of Paris. It was designed by his favourite Italian architect, Domenico da Cortona, who also designed the Château de Chambord in the Loire Valley for the king. The Hôtel de Ville was not finished until 1628. Cortona also designed the first Renaissance church in Paris, the church of Saint-Eustache (1532) by covering a Gothic structure with flamboyant Renaissance detail and decoration. The first Renaissance house in Paris was the Hôtel Carnavalet, begun in 1545. It was modelled after the Grand Ferrare, a mansion in Fontainebleau designed by Italian architect Sebastiano Serlio. It is now the Carnavalet Museum.

In 1534, Francis I became the first French king to make the Louvre his residence; he demolished the massive central tower to create an open courtyard. Near the end of his reign, Francis decided to build a new wing with a Renaissance façade in place of one wing built by King Philip II. The new wing was designed by Pierre Lescot, and it became a model for other Renaissance façades in France. Francis also reinforced the position of Paris as a center of learning and scholarship. In 1500, there were seventy-five printing houses in Paris, second only to Venice, and later in the 16th century, Paris brought out more books than any other European city. In 1530, Francis created a new faculty at the University of Paris with the mission of teaching Hebrew, Greek and mathematics. It became the Collège de France.

Francis I died in 1547, and his son, Henry II, continued to decorate Paris in the French Renaissance style: the finest Renaissance fountain in the city, the Fontaine des Innocents, was built to celebrate Henry's official entrance into Paris in 1549. Henry II also added a new wing to the Louvre, the Pavillon du Roi, to the south along the Seine. The bedroom of the king was on the first floor of this new wing. He also built a magnificent hall for festivities and ceremonies, the Salle des Cariatides, in the Lescot Wing. He also began construction of a new wall around the growing city, which was not finished until the reign of Louis XIII.

Henry II died 10 July 1559 from wounds suffered while jousting at his residence at the Hôtel des Tournelles. His widow, Catherine de Medicis, had the old residence demolished in 1563. In 1612, construction began on the Place des Vosges, one of the oldest planned squares in Paris. Between 1564 and 1572 she constructed a new royal residence, the Tuileries Palace perpendicular to the Seine, just outside the wall built by Charles V around the city. To the west of the palace she created a large Italian-style garden, the Jardin des Tuileries. She abruptly abandoned the palace in 1574, due to the prophecy of an astrologer that she would die close to the church of Saint-Germain, or Saint-Germain-l'Auxerois. She began building a new palace on rue de Viarmes, near Les Halles, but it was never finished, and all that remains is a single column.

The second part of the 16th century in Paris was largely dominated by what became known as the French Wars of Religion (1562–1598). During the 1520s, the writings of Martin Luther began to circulate in the city, and the doctrines known as Calvinism attracted many followers, especially among the French upper classes. The Sorbonne and University of Paris, the major fortresses of Catholic orthodoxy, fiercely attacked the Protestant and humanist doctrines. The scholar Etienne Dolet was burned at the stake, along with his books, on place Maubert in 1532, on the orders of the theology faculty of the Sorbonne; and many others followed, but the new doctrines continued to grow in popularity.

Henry II was succeeded briefly by Francis II, who reigned from 1559 to 1560; then by Charles IX, from 1560 to 1574, who, under the guidance of their mother, Catherine de Medici, tried at times to reconcile Catholics and Protestants. and at other times, to eliminate them completely. Paris was the stronghold of the Catholic League. On the night of August 23–24, 1572, while many prominent Protestants from all over France were in Paris on the occasion of the marriage of Henri of Navarre—the future Henry IV—to Margaret of Valois, sister of Charles IX, the royal council decided to assassinate the leaders of the Protestants. The targeted killings quickly turned into a general slaughter of Protestants by Catholic mobs, known as St. Bartholomew's Day massacre, and continued through August and September, spreading from Paris to the rest of the country. About three thousand Protestants were massacred by mobs in the streets of Paris, and five to ten thousand elsewhere in France.

Paris had suffered greatly during the wars of religion; a third of the Parisians had fled; the population was estimated to be 300,000 in 1600. Many houses were destroyed, and the grand projects of the Louvre, the Hôtel de Ville, and the Tuileries Palace were unfinished. Henry began a series of major new projects to improve the functioning and appearance of the city, and to win over the Parisians to his side. The Paris building projects of Henry IV were managed by his forceful superintendent of buildings, a Protestant and a general, Maximilien de Béthune, Duke of Sully.

Henry IV recommenced the construction of the Pont Neuf, which had been begun by Henry III in 1578, but had stopped during the wars of religion. It was finished between 1600 and 1607, and was the first Paris bridge without houses and with sidewalks. Near the bridge, he built La Samaritaine (1602–1608), a large pumping station which provided drinking water, as well as water for the gardens of the Louvre and the Tuileries Gardens.

Henry and his builders also decided to add an innovation to the Paris cityscape; three new residential squares, modeled after those in Italian Renaissance cities. On the vacant site of the old royal residence of Henri II, the Hôtel des Tournelles, he built an elegant new residential square surrounded by brick houses and an arcade. It was built between 1605 and 1612, and was named Place Royale, renamed Place des Vosges in 1800. In 1607, he began work on a new residential triangle, Place Dauphine, lined by thirty-two brick and stone houses, near the end of the Île de la Cité. A third square, Place de France, was planned for a site near the old Temple, but was never built.

Place Dauphine was Henry's last project for the city of Paris. The more fervent factions of the Catholic hierarchy in Rome and in France had never accepted Henry's authority, and there were seventeen unsuccessful attempts to kill him. The eighteenth attempt, on May 14, 1610 by François Ravaillac, a Catholic fanatic, while the King's carriage was blocked in traffic on rue de la Ferronnerie, was successful. Four years later, a bronze equestrian statue of the murdered king was erected on the bridge he had constructed at the Île de la Cité western point, looking toward Place Dauphine.

After the death of Charles IX, Henry III attempted to find a peaceful solution, which caused the Catholic party to distrust him. The King was forced to flee Paris by Duke of Guise and his ultra-Catholic followers on May 12, 1588, the so-called Day of the Barricades. On August 1, 1589, Henry III was assassinated in the Château de Saint-Cloud by a Dominican friar, Jacques Clément, bringing the Valois line to an end.

Paris, along with the other towns of the Catholic League, refused to accept the authority of the new King, Henry IV, a Protestant, who had succeeded Henry III. Henry first defeated the ultra-Catholic army at the battle of Ivry on March 14, 1590, and then proceeded to lay siege to Paris. The siege was long and unsuccessful; to end it, Henry IV agreed to convert to Catholicism, with the famous (but perhaps apocryphal) expression "Paris is well worth a Mass". On March 14, 1594, Henry IV entered Paris, after having been crowned King of France at the cathedral of Chartres on February 27, 1594.

Once he was established in Paris, Henry did all that he could to re-establish peace and order in the city, and to win the approval of the Parisians. He permitted the Protestants to open churches far from the center of the city, continued work on the Pont Neuf, and began to plan two Renaissance-style residential squares, Place Dauphine and Place des Vosges, which were not built until the 17th century.

Louis XIII was a few months short of his ninth birthday when his father was assassinated. His mother, Marie de' Medici, became Regent and ruled France in his name. Marie de' Medicis decided to build a residence for herself, the Luxembourg Palace, on the sparsely-populated left bank. It was constructed between 1615 and 1630, and modelled after the Pitti Palace in Florence. She commissioned the most famous painter of the period, Peter Paul Rubens, to decorate the interior with huge canvases of her life with Henry IV (now on display in the Louvre). She ordered the construction of a large Italian Renaissance garden around her palace, and commissioned a Florentine fountain-maker, Tommaso Francini, to create the Medici Fountain. Water was scarce in the Left Bank, one reason that part of the city had grown more slowly than the Right Bank. To provide water for her gardens and fountains, Marie de Medicis had the old Roman aqueduct from Rungis reconstructed. Thanks largely to her presence on the left bank, and the availability of water, noble families began to build houses on the left bank, in a neighborhood that became known as the Faubourg Saint-Germain. In 1616, she created another reminder of Florence on the right bank; the Cours la Reine, a long tree-shaded promenade along the Seine west of the Tuileries Gardens.

Louis XIII entered his fourteenth year in 1614 and exiled his mother to the Château de Blois in the Loire Valley. Marie de' Medici managed to escape from her exile in the Château de Bois, and was reconciled with her son. Louis tried several different heads of government before finally selecting the Cardinal de Richelieu, a protege of his mother, in April 1624. Richelieu quickly showed his military skills and gift for political intrigue by defeating the Protestants at La Rochelle in 1628 and by executing or sending into exile several high-ranking nobles who challenged his authority.

In 1630, Richelieu turned his attention to completing and beginning new projects for the improvement of Paris. Between 1614 and 1635, four new bridges were built over the Seine; the Pont Marie, the Pont de la Tournelle, the Pont au Double, and the Pont Barbier. Two small islands in the Seine, the Île Notre-Dame and the Île-aux-vaches, which had been used for grazing cattle and storing firewood, were combined to make the Île Saint-Louis, which became the site of the splendid hôtels particuliers of Parisian financiers.

Louis XIII and Richelieu continued the rebuilding of the Louvre project begun by Henri IV. In the center of the old medieval fortress, where the great round tower had been, he created the harmonious Cour Carrée, or square courtyard, with its sculpted facades. In 1624, Richelieu began construction of a palatial new residence for himself in the center of the city, the Palais-Cardinal, which on his death was willed to the King and became the Palais-Royal. He began by buying a large mansion, the Hôtel de Rambouillet, to which he added an enormous garden, three times larger than the present Palais-Royal garden, ornamented with a fountain in the center, flowerbeds and rows of ornamental trees, and surrounded by arcades and buildings. In 1629, once the construction of the new palace was underway, land was cleared and construction of a new residential neighborhood began nearby, the quartier Richelieu, near the Porte Saint-Honoré. Other members of the Nobility of the Robe (mostly members of government councils and the courts) built their new residences in the Marais, close to the Place Royale.

During the first part of the regime of Louis XIII Paris prospered and expanded, but the beginning of French involvement the Thirty Years' War against the Holy Roman Empire and the Habsburgs in 1635 brought heavy new taxes and hardships. The French Army was defeated by the Habsburg-ruled Spanish on August 15, 1636, and for several months a Spanish army threatened Paris. The King and Richelieu became increasingly unpopular with the Parisians. Richelieu died in 1642, and Louis XIII six months later in 1643.

Richelieu died in 1642, and Louis XIII in 1643. At the death of his father, Louis XIV was only five years old, and his mother Anne of Austria became regent. Richelieu's successor, Cardinal Mazarin, tried to impose a new tax upon the Parlement of Paris, which consisted of a group of prominent nobles of the city. When they refused to pay, Mazarin had the leaders arrested. This marked the beginning a long uprising, known as the Fronde, that pitted the Parisian nobility against royal authority. It lasted from 1648 to 1653.

At times, the young Louis XIV was held under virtual house arrest in the Palais-Royal. He and his mother were forced to flee the city twice, in 1649 and 1651, to the royal château at Saint-Germain-en-Laye, until the army could retake control of Paris. As a result of the Fronde, Louis XIV had a profound lifelong distrust of Paris. He moved his Paris residence from the Palais-Royal to the more secure Louvre and then, in 1671, he moved the royal residence out of the city to Versailles and came into Paris as seldom as possible.

Despite the distrust of the king, Paris continued to grow and prosper, reaching a population of between 400,000 and 500,000. The king named Jean-Baptiste Colbert as his new Superintendent of Buildings, and Colbert began an ambitious building programme to make Paris the successor to ancient Rome. To make his intention clear, Louis XIV organised a festival in the carrousel of the Tuileries in January 1661, in which he appeared, on horseback, in the costume of a Roman Emperor, followed by the nobility of Paris. Louis XIV completed the Cour carrée of the Louvre and built a majestic row of columns along its east façade (1670). Inside the Louvre, his architect Louis Le Vau and his decorator Charles Le Brun created the Gallery of Apollo, the ceiling of which featured an allegoric figure of the young king steering the chariot of the sun across the sky. He enlarged the Tuileries Palace with a new north pavilion, and had André Le Nôtre, the royal gardener, remodel the gardens of the Tuileries.

Across the Seine from the Louvre, Louis XIV built the Collège des Quatre-Nations (College of the Four Nations) (1662–1672), an ensemble of four baroque palaces and a domed church, to house sixty young noble students coming to Paris from four provinces recently attached to France (today it is the Institut de France). In the center of Paris, Colbert constructed two monumental new squares, Place des Victoires (1689) and Place Vendôme (1698). He built a new hospital for Paris, La Salpêtrière, and, for wounded soldiers, a new hospital complex with two churches, Les Invalides (1674). Of the two hundred million livres that Louis spent on buildings, twenty million were spent in Paris; ten million for the Louvre and the Tuileries; 3.5 million for the new royal Gobelins Manufactory and the Savonnerie, 2 million for Place Vendôme, and about the same for the churches of Les Invalides. Louis XIV made his final visit to Paris in 1704 to see Les Invalides under construction.

For the poor of Paris, life was very different. They were crowded into tall, narrow, five- or six-story high buildings that lined the winding streets on the Île de la Cité and other medieval quarters of the city. Crime in the dark streets was a serious problem. Metal lanterns were hung in the streets, and Colbert increased to four hundred the number of archers who acted as night watchmen. Gabriel Nicolas de la Reynie was appointed the first lieutenant-general of police of Paris in 1667, a position he held for thirty years; his successors reported directly to the king.

In the 18th century, Paris was the center of an explosion of philosophic and scientific activity known as the Age of Enlightenment. Denis Diderot and Jean le Rond d'Alembert published their Encyclopédie in 1751–52. It provided intellectuals across Europe with a high quality survey of human knowledge. The Montgolfier brothers launched the first manned flight in a hot-air balloon on 21 November 1783, from the Château de la Muette, near the Bois de Boulogne. Paris was the financial capital of France and continental Europe, the primary European center of book publishing, fashion, and the manufacture of fine furniture and luxury goods. Parisian bankers funded new inventions, theatres, gardens, and works of art. The successful Parisian playwright Pierre de Beaumarchais, the author of The Barber of Seville, helped fund the American Revolution.

The first café in Paris had been opened in 1672, and by the 1720s there were around 400 cafés in the city. They became meeting places for the city's writers and scholars. The Café Procope was frequented by Voltaire, Jean-Jacques Rousseau, Diderot and d’Alembert. They became important centres for exchanging news, rumors and ideas, often more reliable than the newspapers of the day.

By 1763, the Faubourg Saint-Germain had replaced Le Marais as the most fashionable residential neighborhood for the aristocracy and the wealthy, who built magnificent private mansions, most of which later became government residences or institutions: the Hôtel d'Évreux (1718–1720) became the Élysée Palace, the residence of the presidents of the French Republic; the Hôtel Matignon, the residence of the prime minister; the Palais Bourbon, the seat of the National Assembly; the Hôtel Salm, the Palais de la Légion d'Honneur; and the Hôtel de Biron eventually became the Rodin Museum.

Louis XIV died on 1 September 1715. His nephew, Philippe d'Orléans, the regent for the five-year-old King Louis XV, moved the royal residence and government back to Paris, where it remained for seven years. The king lived in the Tuileries Palace, while the regent lived in his family's luxurious Parisian residence, the Palais-Royal (the former Palais-Cardinal of Cardinal Richelieu). He made one important contribution to Paris intellectual life. In 1719, he moved the Royal library to the Hôtel de Nevers near the Palais-Royal, where it eventually became part of the Bibliothèque nationale de France (National Library of France). On 15 June 1722, distrustful of the turbulence in Paris, the regent moved the court back to Versailles. Afterwards, Louis XV visited the city only on special occasions.

One of the major building projects in Paris of Louis XV and his successor, Louis XVI, was the new church of Sainte Geneviève on top of the Montagne Sainte-Geneviève on the Left Bank, the future Panthéon. The plans were approved by the king in 1757 and work continued until the French Revolution. Louis XV also built an elegant new military school, the École Militaire (1773), a new medical school, the École de Chirurgie (1775), and a new mint, the Hôtel des Monnaies (1768), all on the Left Bank.

Under Louis XV, the city expanded westward. A new boulevard, the Champs-Élysées, was laid out from the Tuileries Garden to the Rond-Point on the Butte (now the Place de l'Étoile) and then to the Seine to create a straight line of avenues and monuments known as Paris historical axis. At the beginning of the boulevard, between the Cours-la-Reine and the Tuileries gardens, a large square was created between 1766 and 1775, with an equestrian statue of Louis XV in the center. It was first called "Place Louis XV", then the "Place de la Révolution" after 10 August 1792, and finally the Place de la Concorde in 1795 at the time of the Directoire.

Between 1640 and 1789, Paris grew in population from 400,000 to 600,000. It was no longer the largest city in Europe; London passed it in population in about 1700, but it was still growing at a rapid rate, due largely to migration from the Paris basin and from the north and east of France. The center of the city became more and more crowded; building lots became smaller and buildings taller, up to four, five and even six stories. In 1784, the height of buildings was finally limited to nine toises, or about eighteen meters.

In the summer of 1789, Paris became the center stage of the French Revolution and events that changed the history of France and Europe. In 1789, the population of Paris was between 600,000 and 640,000. Then as now, most wealthier Parisians lived in the western part of the city, the merchants in the center, and the workers and artisans in the southern and eastern parts, particularly the Faubourg Saint-Honoré. The population included about one hundred thousand extremely poor and unemployed persons, many of whom had recently moved to Paris to escape hunger in the countryside. Known as the sans-culottes, they made up as much as a third of the population of the eastern neighborhoods and became important actors in the Revolution.

On 11 July 1789, soldiers of the Royal-Allemand regiment attacked a large but peaceful demonstration on the Place Louis XV organized to protest the dismissal by the king of his reformist finance minister Jacques Necker. The reform movement turned quickly into a revolution. On 13 July, a crowd of Parisians occupied the Hôtel de Ville, and the Marquis de Lafayette organized the French National Guard to defend the city. On 14 July, a mob seized the arsenal at the Invalides, acquired thousands of guns, and stormed the Bastille, a prison that was a symbol of royal authority, but at that time held only seven prisoners. 87 revolutionaries were killed in the fighting.

On 5 October 1789, a large crowd of Parisians marched to Versailles and, the following day, brought the royal family and government back to Paris, virtually as prisoners. The new government of France, the National Assembly, began to meet in the Salle du Manège near the Tuileries Palace on the outskirts of the Tuileries garden.

In April 1792, Austria declared war on France, and in June 1792, the Duke of Brunswick, commander of the army of the King of Prussia, threatened to destroy Paris unless the Parisians accepted the authority of their king. In response to the threat from the Prussians, on 10 August the leaders of the sans-culottes deposed the Paris city government and established their own government, the Insurrectionary Commune, in the Hôtel-de-Ville. Upon learning that a mob of sans-culottes was approaching the Tuileries Palace, the royal family took refuge at the nearby Assembly. In the attack of the Tuileries Palace, the mob killed the last defenders of the king, his Swiss Guards, then ransacked the palace. Threatened by the sans-culottes, the Assembly "suspended" the power of the king and, on 11 August, declared that France would be governed by a National Convention. On 13 August, Louis XVI and his family were imprisoned in the Temple fortress. On 21 September, at its first meeting, the Convention abolished the monarchy, and the next day declared France to be a republic.

The new government imposed a Reign of Terror upon France. From 2 to 6 September 1792, bands of sans-culottes broke into the prisons and murdered refractory priests, aristocrats and common criminals. On 21 January 1793, Louis XVI was guillotined on the Place de la Révolution. Marie Antoinette was executed on the same square on 16 October 1793. Bailly, the first Mayor of Paris, was guillotined the following November at the Champ de Mars. During the Reign of Terror, 16,594 persons were tried by the revolutionary tribune and executed by the guillotine. Tens of thousands of others associated with the Ancien Régime were arrested and imprisoned. Property of the aristocracy and the Church was confiscated and declared Biens nationaux (national property). The churches were closed.

A new government, the Directory, took the place of the Convention. It moved its headquarters to the Luxembourg Palace and limited the autonomy of Paris. When the authority of the Directory was challenged by a royalist uprising on 13 Vendémiaire, Year IV (5 October 1795), the Directory called upon a young general, Napoléon Bonaparte, for help. Bonaparte used cannon and grapeshot to clear the streets of demonstrators. On 18 Brumaire, Year VIII (9 November 1799), he organised a coup d'état that overthrew the Directory and replaced it by the Consulate with Bonaparte as First Consul. This event marked the end of the French Revolution and opened the way to the First French Empire.

First Consul Napoleon Bonaparte moved into the Tuileries Palace on 19 February 1800 and immediately began to re-establish calm and order after the years of uncertainty and terror of the Revolution. He made peace with the Catholic Church; masses were held again in the Cathedral of Notre Dame, priests were allowed to wear ecclesiastical clothing again, and churches to ring their bells. To re-establish order in the unruly city, he abolished the elected position of the Mayor of Paris, and replaced it with a Prefect of the Seine and a Prefect of Police, both appointed by him. Each of the twelve arrondissements had its own mayor, but their power was limited to enforcing the decrees of Napoleon's ministers.

After he crowned himself Emperor on December 2, 1804, Napoleon began a series of projects to make Paris into an imperial capital to rival ancient Rome. He built monuments to French military glory, including the Arc de Triomphe du Carrousel, the column in Place Vendôme, and the future church of the Madeleine, intended as a temple to military heroes; and began the Arc de Triomphe. To improve the circulation of traffic in central Paris, he built a wide new street, Rue de Rivoli, from the Place de la Concorde to the Place des Pyramides. He made important improvements to the city's sewers and water supply, including a canal from the Ourcq River, and the construction of a dozen new fountains, including the Fontaine du Palmier on Place du Châtelet; and three new bridges; the Pont d'Iéna, Pont d'Austerlitz, including the Pont des Arts (1804), the first iron bridge in Paris. The Louvre became the Napoleon Museum, in a wing of the former palace, displaying many works of art he brought back from his military campaigns in Italy, Austria, Holland and Spain; and he militarized and re-organized the Grandes écoles, to train engineers and administrators.

Between 1801 and 1811, the population of Paris grew from 546,856 to 622,636, nearly the population before the French Revolution, and by 1817 it reached 713,966. During Napoleon's reign, Paris suffered from war and blockade, but retained its position as a European capital of fashion, art, science, education, and commerce. After his downfall in 1814, the city was occupied by the Prussian, English and German armies. The symbols of the monarchy were restored, but most of Napoleon's monuments and some of his new institutions, including the form of city government, the fire department, and the modernized Grandes écoles, survived.

Following the downfall of Napoleon after the defeat of Waterloo on 18 June 1815, 300,000 soldiers of the Seventh Coalition armies from England, Austria, Russia and Prussia occupied Paris and remained until December 1815. Louis XVIII returned to the city and moved into the former apartments of Napoleon at the Tuileries Palace. The Pont de la Concorde was renamed "Pont Louis XVI", a new statue of Henry IV was put back on the empty pedestal on the Pont Neuf, and the white flag of the Bourbons flew from the top of the column in Place Vendôme.

The aristocrats who had emigrated returned to their town houses in the Faubourg Saint-Germain, and the cultural life of the city quickly resumed, though on a less extravagant scale. A new opera house was constructed on Rue Le Peletier. The Louvre was expanded in 1827 with nine new galleries that put on display the antiquities collected during Napoleon's conquest of Egypt.

Work continued on the Arc de Triomphe, and the new churches in the neoclassical style were constructed to replace those destroyed during the Revolution: Saint-Pierre-du-Gros-Caillou (1822–1830); Notre-Dame-de-Lorette (1823–1836); Notre-Dame de Bonne-Nouvelle (1828–1830); Saint-Vincent-de-Paul (1824–1844) and Saint-Denys-du-Saint-Sacrement (1826–1835). The Temple of Glory (1807) created by Napoleon to celebrate military heroes was turned back into a church, the church of La Madeleine. King Louis XVIII also built the Chapelle expiatoire, a chapel devoted to Louis XVI and Marie-Antoinette, on the site of the small Madeleine cemetery, where their remains (now in the Basilica of Saint-Denis) were buried following their execution.

Paris grew quickly, and passed 800,000 in 1830. Between 1828 and 1860, the city built a horse-drawn omnibus system that was the world's first mass public transit system. It greatly speeded the movement of people inside the city and became a model for other cities. The old Paris street names, carved into stone on walls, were replaced by royal blue metal plates with the street names in white letters, the model still in use today. Fashionable new neighborhoods were built on the right bank around the church of Saint-Vincent-de-Paul, the church of Notre-Dame-de-Lorette, and the Place de l’Europe. The "New Athens" neighbourhood became, during the Restoration and the July Monarchy, the home of artists and writers: the actor François-Joseph Talma lived at number 9 Rue de la Tour-des-Dames; the painter Eugène Delacroix lived at 54 Rue Notre-Dame de-Lorette; the novelist George Sand lived in the Square d'Orléans. The latter was a private community that opened at 80 Rue Taitbout, which had forty-six apartments and three artists' studios. Sand lived on the first floor of number 5, while Frédéric Chopin lived for a time on the ground floor of number 9.

Louis XVIII was succeeded by his brother Charles X in 1824, but new the government became increasingly unpopular with both the upper classes and the general population of Paris. The play Hernani (1830) by the twenty-eight-year-old Victor Hugo, caused disturbances and fights in the theater audience because of its calls for freedom of expression. On 26 July, Charles X signed decrees limiting freedom of the press and dissolving the Parliament, provoking demonstrations which turned into riots which turned into a general uprising. After three days, known as the ‘’Trois Glorieuses’’, the army joined the demonstrators. Charles X, his family and the court left the Château de Saint-Cloud, and, on 31 July, the Marquis de Lafayette and the new constitutional monarch Louis-Philippe raised the tricolor flag again before cheering crowds at the Hôtel de Ville.

Paris during the reign of King Louis-Philippe (1830-1848) was the city described in the novels of Honoré de Balzac and Victor Hugo. Its population increased from 785,000 in 1831 to 1,053,000 in 1848, as the city grew to the north and west, while the poorest neighborhoods in the center became even more crowded.The heart of the city, around the Île de la Cité, was a maze of narrow, winding streets and crumbling buildings from earlier centuries; it was picturesque, but dark, crowded, unhealthy and dangerous. A cholera outbreak in 1832 killed 20,000 people. Claude-Philibert de Rambuteau, prefect of the Seine for fifteen years under Louis-Philippe, made tentative efforts to improve the center of the city: he paved the quays of the Seine with stone paths and planted trees along the river. He built a new street (now the Rue Rambuteau) to connect the Marais district with the markets and began construction of Les Halles, the famous central food market of Paris, finished by Napoleon III.Louis-Philippe lived in his old family residence, the Palais-Royal, until 1832, before moving to the Tuileries Palace. His chief contribution to the monuments of Paris was the completion in 1836 of the Place de la Concorde, which was further embellished on 25 October 1836 by the placement of the Luxor Obelisk. In the same year, at the other end of the Champs-Élysées, Louis-Philippe completed and dedicated the Arc de Triomphe, which had been begun by Napoleon I.The ashes of Napoleon were returned to Paris from Saint Helena in a solemn ceremony on 15 December 1840, and Louis-Philippe built an impressive tomb for them at the Invalides. He also placed the statue of Napoleon on top of the column in the Place Vendôme. In 1840, he completed a column in the Place de la Bastille dedicated to the July 1830 revolution which had brought him to power. He also sponsored the restoration of the Paris churches ruined during the French Revolution, a project carried out by the ardent architectural historian Eugène Viollet-le-Duc; the first church slated for restoration was the Abbey of Saint-Germain-des-Prés.

In December 1848, Louis-Napoleon Bonaparte, the nephew of Napoleon I, became the first elected President of France, winning seventy-four percent of the vote. At the beginning of Napoleon's reign, Paris had a population of about one million people, most of whom lived in crowded and unhealthy conditions. A cholera epidemic in the overcrowded center in 1848 killed twenty thousand people. In 1853, Napoleon launched a gigantic public works program under the direction of his new Prefect of the Seine, Georges-Eugène Haussmann, whose purpose was to put unemployed Parisians to work and bring clean water, light and open space to the centre of the city.

Napoleon began by enlarging the city limits beyond the twelve arrondissements established in 1795. The towns around Paris had resisted becoming part of the city, fearing higher taxes; Napoleon used his new imperial power to annex them, adding eight new arrondissements to the city and bringing it to its present size. Over the next seventeen years, Napoleon and Haussmann transformed entirely the appearance of Paris. They demolished most of the old neighborhoods on the Île de la Cité, replacing them with a new Palais de Justice and prefecture of police, and rebuilding the old city hospital, the Hôtel-Dieu. They completed the extension of the Rue de Rivoli, begun by Napoleon I, and built a network of wide boulevards to connect the railway stations and neighborhoods of the city to improve traffic circulation and create open space around the city's monuments. The new boulevards also made it harder to build barricades in the neighborhoods prone to uprisings and revolutions, but, as Haussmann himself wrote, this was not the main purpose of the boulevards. Haussmann imposed strict standards on the new buildings along the new boulevards; they had to be the same height, follow the same basic design, and be faced in a creamy white stone. These standards gave central Paris the street plan and distinctive look it still retains today.

Napoleon III also wanted to give the Parisians, particularly those in the outer neighborhoods, access to green space for recreation and relaxation. He was inspired by Hyde Park in London, which he had often visited when he was in exile there. He ordered the construction of four large new parks at the four cardinal points of the compass around the city; the Bois de Boulogne to the west; the Bois de Vincennes to the east; the Parc des Buttes-Chaumont to the north; and Parc Montsouris to the south, plus many smaller parks and squares around the city, so that no neighbourhood was more than a ten-minute walk from a park.

Napoleon III and Haussmann rebuilt two major railway stations, the Gare de Lyon and the Gare du Nord, to make them monumental gateways to the city. They improved the sanitation of the city by building new sewers and water mains under the streets and built a new reservoir and aqueduct to increase the supply of fresh water. In addition, they installed tens of thousands of gaslights to illuminate the streets and monuments. They began construction of the Palais Garnier for the Paris Opera and built two new theaters at the Place du Châtelet to replace those in the old theater district of the Boulevard du Temple, known as "The Boulevard of Crime", which had been demolished to make room for the new boulevards. They completely rebuilt the central market of the city, Les Halles, built the first railway bridge over the Seine, and also built the monumental Fontaine Saint-Michel at the beginning of the new Boulevard Saint-Michel. They also redesigned the street architecture of Paris, installing new street lamps, kiosks, omnibus stops and public toilets (called "chalets of necessity"), which were specially designed by the city architect Gabriel Davioud, and which gave the Paris boulevards their distinct harmony and look.

In the late 1860s, Napoleon III decided to liberalize his regime and gave greater freedom and power to the legislature. Haussmann became the chief target of criticism in the parliament, blamed for the unorthodox ways in which he financed his projects, for amputating four hectares from the thirty hectares of the Luxembourg Gardens in order to make room for new streets, and for the general inconvenience his projects caused to Parisians for nearly two decades. In January 1870, Napoleon was forced to dismiss him. A few months later, Napoleon was drawn into the Franco-Prussian War, then defeated and captured at the Battle of Sedan of 1–2 September 1870, but the work on Haussmann's boulevards continued during the Third Republic, which was established immediately after Napoleon's defeat and abdication, until they were finally finished in 1927.

In the second half of the 19th century, Paris hosted five international expositions that attracted millions of visitors and made Paris an increasingly important center of technology, trade, and tourism. The Expositions celebrated the cult of technology and industrial production, both through the impressive iron architecture in which the exhibits were displayed and the almost demonic energy of machines and installations in place.

The first was the Universal Exposition of 1855, hosted by Napoleon III, held in the gardens next to the Champs Élysées. It was inspired by the London's Great Exhibition in 1851 and was designed to showcase the achievements of French industry and culture. The classification system of Bordeaux wines was developed especially for the Exposition. The Théâtre du Rond-Point next to the Champs Élysées is a vestige of that exposition.

The Paris International Exposition in 1867. Famous visitors included Czar Alexander II of Russia, Otto Von Bismarck, Kaiser William I of Germany, King Louis II of Bavaria and the Sultan of the Ottoman Empire, the first foreign trip ever made by an Ottoman ruler. The Bateaux Mouches excursion riverboats made their first journeys on the Seine during the 1867 Exposition.

The Universal Exposition of 1878 took place on both sides of the Seine, in the Champ de Mars and the heights of Trocadéro, where the first Palais de Trocadéro was built. Alexander Graham Bell displayed his new telephone, Thomas Edison presented his phonograph, and the head of the newly-finished Statue of Liberty was displayed before it was sent to New York to be attached to the body. In honor of the Exposition, the Avenue de l’Opéra and Place de l’Opéra were lit with electric lights for the first time. The Exposition attracted thirteen million visitors.

The Universal Exposition of 1889, which also took place on the Champ de Mars, celebrated the centenary of the beginning of the French Revolution. The most memorable feature was the Eiffel Tower, 300 meters tall when it opened (now 324 with the addition of broadcast antennas), which served as the gateway to the Exposition. The Eiffel Tower remained the world's tallest structure until 1930. It was not popular with everyone: its modern style was denounced in public letters by many of France's most prominent cultural figures, including Guy de Maupassant, Charles Gounod and Charles Garnier. Other popular exhibits included the first musical fountain, lit with colored electric lights, changing in time to music. Buffalo Bill and sharpshooter Annie Oakley drew large crowds to their Wild West Show at the Exposition.

The Universal Exposition of 1900 celebrated the turn of the century. It also took place at the Champ de Mars and attracted fifty million visitors. In addition to the Eiffel Tower, the Exposition featured the world's largest ferris wheel, the Grande Roue de Paris, one hundred metres high, carrying 1,600 passengers in 40 cars. Inside the exhibit hall, Rudolph Diesel demonstrated his new engine, and the first escalator was on display. The Exposition coincided with the 1900 Paris Olympics, the first time that the Olympic games were held outside of Greece. It also popularised a new artistic style, Art nouveau, to the world. Two architectural legacies of the Exposition, the Grand Palais and Petit Palais, are still in place.

On 23 July 1873, the National Assembly endorsed the project of building a basilica at the site where the uprising of the Paris Commune had begun; it was intended to atone for the sufferings of Paris during the Franco-Prussian War and the Commune. The Basilica of Sacré-Cœur was built in a neo-Byzantine style and paid for by public subscription. It was not finished until 1919, but quickly became one of the most recognizable landmarks in Paris.

Radical Republicans dominated the Paris municipal elections of 1878, winning 75 of the 80 municipal council seats. In 1879, they changed the name of many of the Paris streets and squares: the Place du Château-d’Eau became the Place de la République, and a statue of the Republic was placed in the centre in 1883. The avenues de la Reine-Hortense, Joséphine and Roi-de-Rome were renamed Hoche, Marceau and Kléber, after generals who served during the period of the French Revolution. The Hôtel de Ville was rebuilt between 1874 and 1882 in the neo-Renaissance style, with towers modelled after those of the Château de Chambord. The ruins of the Cour des Comptes on the Quai d'Orsay, burned by the Communards, were demolished and replaced by a new railway station, the Gare d'Orsay (today's Musée d'Orsay). The walls of the Tuileries Palace were still standing. Baron Haussmann, Hector Lefuel and Eugène Viollet-le-Duc pleaded for the rebuilding of the palace but, in 1879, the city council decided against it, because the former palace was a symbol of monarchy. In 1883, it had the ruins pulled down. Only the Pavillon de Marsan (north) and the Pavillon de Flore (south) were restored.

During the Franco-Prussian War of 1870 to 1871, the French National Guard had defended Paris, and working-class radicalism grew among its soldiers. Following the establishment of the Third Republic in September 1870 (under French chief executive Adolphe Thiers from February 1871) and the complete defeat of the French Army by the Germans by March 1871, soldiers of the National Guard seized control of the city on March 18. They killed two French army generals and refused to accept the authority of the Third Republic, instead attempting to establish an independent government.

The Commune governed Paris for two months, establishing policies that tended toward a progressive, anti-religious system of social democracy, including the separation of church and state, self-policing, the remission of rent, the abolition of child labor, and the right of employees to take over an enterprise deserted by its owner. The Roman Catholic Churches and schools were closed. Feminist, socialist, communist and anarchist currents played important roles in the Commune. However, the various Communards had little more than two months to achieve their respective goals.

The national French Army suppressed the Commune at the end of May during La semaine sanglante ("The Bloody Week") beginning on 21 May 1871. The national forces killed in battle or quickly executed between 10,000 and 15,000 Communards, though one unconfirmed estimate from 1876 put the toll as high as 20,000. In its final days, the Commune executed the Archbishop of Paris, Georges Darboy, and about one hundred hostages, mostly gendarmes and priests. 43,522 Communards were taken prisoner, including 1,054 women. More than half were quickly released. Fifteen thousand were tried, 13,500 of whom were found guilty. Ninety-five were sentenced to death, 251 to forced labor, and 1,169 to deportation (mostly to New Caledonia). Thousands of other Commune members, including several of the leaders, fled abroad, mostly to England, Belgium and Switzerland. All the prisoners and exiles received pardons in 1880 and could return home, where some resumed political careers.

Debates over the policies and outcome of the Commune had significant influence on the ideas of Karl Marx (1818–1883) and Friedrich Engels (1820–1895), who described it as the first example of the dictatorship of the proletariat. Engels wrote: "Of late, the Social-Democratic philistine has once more been filled with wholesome terror at the words: Dictatorship of the Proletariat. Well and good, gentlemen, do you want to know what this dictatorship looks like? Look at the Paris Commune. That was the Dictatorship of the Proletariat."

The outbreak of the First World War in August 1914 saw patriotic demonstrations on the Place de la Concorde and at the Gare de l'Est and Gare du Nord as the mobilized soldiers departed for the front. Within a few weeks, however, the German Army had reached the Marne River, east of Paris. The French government moved to Bordeaux on 2 September, and the great masterpieces of the Louvre were transported to Toulouse.

Early in the First Battle of the Marne, on 5 September 1914 the French army desperately needed reinforcements. General Galieni, the military governor of Paris, lacked trains. He requisitioned buses and, most famously, about 600 Paris taxicabs that were used to carry six thousand troops to the front at Nanteuil-le-Haudouin, fifty kilometers away. Each taxi carried five soldiers following the lights of the taxi ahead, and the mission was accomplished within twenty-four hours. The Germans were surprised and were pushed back by the French and British armies. The number of soldiers transported was small, but the effect on French morale was enormous; it confirmed the solidarity between the people and the army. The government returned to Paris, and theatres and cafés re-opened.

The city was bombed by German heavy Gotha bombers and by Zeppelins. The Parisians suffered epidemics of typhoid and measles; a deadly outbreak of Spanish influenza during the winter of 1918-19 killed thousands of Parisians.

In the spring of 1918, the German army launched a new offensive and threatened Paris once more, bombing it with the Paris Gun. On 29 March 1918, one shell struck the Church of Saint-Gervais and killed 88 persons. Sirens were installed to warn the population of impending bombardments. On 29 June 1917, American soldiers arrived in France to reinforce the French and British armies. The Germans were pushed back once again, and the armistice was declared on 11 November 1918. Hundreds of thousands of Parisians filled the Champs Élysées on 17 November to celebrate the return of Alsace and Lorraine to France. Equally huge crowds welcomed President Woodrow Wilson to the Hôtel de Ville on 16 December. Huge crowds of Parisians also lined the Champs Élysées on 14 July 1919 for a victory parade by the Allied armies.

After the First World War ended in November 1918, to jubilation and profound relief in Paris, unemployment surged, prices soared, and rationing continued. Parisian households were limited to 300 grams of bread per day, and meat only four days a week. A general strike paralyzed the city in July 1919. The Thiers wall, 19th-century fortifications surrounding the city, were demolished in the 1920s and replaced by tens of thousands of low-cost, seven-story public housing units, filled by low-income blue-collar workers. . Paris struggled to regain its old prosperity and gaiety.

The French economy boomed from 1921 until the Great Depression reached Paris in 1931. This period, called Les années folles or the "Crazy Years", saw Paris reestablished as a capital of art, music, literature and cinema. The artistic ferment and low prices attracted writers and artists from around the world, including Pablo Picasso, Salvador Dalí, Ernest Hemingway, James Joyce, and Josephine Baker.

Paris hosted the 1924 Olympic Games, major international expositions in 1925 and 1937, and the Colonial Exposition of 1931, all of which left a mark on Paris architecture and culture.

The worldwide Great Depression hit Paris in 1931, bringing hardships and a more somber mood. The population declined slightly from its all-time peak of 2.9 million in 1921 to 2.8 million in 1936. The arrondissements in the city's center lost as much as 20% of their population, while the outer neighborhoods, or banlieus, grew by 10%. The low birth rate of Parisians was made up by a wave of new immigration from Russia, Poland, Germany, eastern and central Europe, Italy, Portugal and Spain. Political tensions grew in Paris, as seen in strikes, demonstrations and confrontations between the Communists and Front populaire on the extreme left and the Action Française on the extreme right.

Paris started mobilizing for war in September 1939, when Nazi Germany and the Soviet Union attacked Poland, but the war seemed far away until May 10, 1940, when the Germans attacked France and quickly defeated the French army. The French government departed Paris on June 10, and the Germans occupied the city on June 14. During the Occupation, the French Government moved to Vichy, and Paris was governed by the German military and by French officials approved by the Germans. For Parisians, the Occupation was a series of frustrations, shortages and humiliations. A curfew was in effect from nine in the evening until five in the morning; at night, the city went dark. Rationing of food, tobacco, coal and clothing was imposed from September 1940. Every year the supplies grew more scarce and the prices higher. A million Parisians left the city for the provinces, where there was more food and fewer Germans. The French press and radio contained only German propaganda.

The first demonstration against the Occupation, by Paris students, took place on 11 November 1940. As the war continued, anti-German clandestine groups and networks were created, some loyal to the French Communist Party, others to General Charles de Gaulle in London. They wrote slogans on walls, organized an underground press, and sometimes attacked German officers. Reprisals by the Germans were swift and harsh.

Following the Allied invasion of Normandy on June 6, 1944, the French Resistance in Paris launched an uprising on August 19, seizing the police headquarters and other government buildings. The city was liberated by French and American troops on August 25; the next day, General de Gaulle led a triumphant parade down the Champs-Élysées on August 26, and organized a new government. In the following months, ten thousand Parisians who had collaborated with the Germans were arrested and tried, eight thousand convicted, and 116 executed. On 29 April and 13 May 1945, the first post-war municipal elections were held, in which French women voted for the first time.

At the end of the Second World War, most Parisians were living in misery. Industry was ruined, housing was in short supply, and food was rationed. The population of Paris did not return to its 1936 level until 1946, and grew to 2,850,000 by 1954, including 135,000 immigrants, mostly from Algeria, Morocco, Italy and Spain. The exodus of middle-class Parisians to the suburbs continued. The population of the city declined during the 1960s and 1970s before finally stabilizing in the 1980s.

In the 1950s and 1960s, the city underwent a massive reconstruction, with the addition of new highways, skyscrapers, and thousands of new apartment blocks. Beginning in the 1970s, French Presidents took a personal interest leaving a legacy of new museums and buildings: President François Mitterrand had the most ambitious program of any President since Napoleon III. His Grands Travaux included the Arab World Institute (Institut du monde arabe), a new national library called the Bibliothèque François Mitterrand; a new opera house, the Opéra Bastille, a new Ministry of Finance, Ministère de l'Économie et des Finances, in Bercy. The Grande Arche in La Défense and the Grand Louvre, with the addition of the Louvre Pyramid designed by I. M. Pei in the Cour Napoléon.

In the post-war era, Paris experienced its largest development since the end of the Belle Époque in 1914. The suburbs began to expand considerably, with the construction of large social estates known as cités and the beginning of La Défense, the business district. A comprehensive express subway network, the Réseau Express Régional (RER), was built to complement the Métro and serve the distant suburbs. A network of roads was developed in the suburbs centered on the Périphérique expressway encircling the city, which was completed in 1973.

In May 1968, a student uprising in Paris led to major changes in the educational system, and the breakup of the University of Paris into separate campuses.

Paris had not had an elected Mayor since the French Revolution. Napoleon Bonaparte and his successors had personally chosen the Prefect to run the city. Under President Valéry Giscard d'Estaing, the law was changed on December 31, 1975. The first mayoral election in 1977 was won by Jacques Chirac, the former Prime Minister. Chirac served as Mayor of Paris for eighteen years, until 1995, when he was elected President of the Republic.