Frederick I of Prussia, born on 11 July 1657 in Königsberg, was the third son of Frederick William, Elector of Brandenburg, and Louise Henriette of Orange-Nassau. He became Elector Frederick III of Brandenburg and Duke of Prussia upon his father's death on 29 April 1688. Shortly after his ascension, he founded a new city named Friedrichstadt, located south of Dorotheenstadt.Frederick I opposed France, contrasting with his father's pro-French stance. He joined the League of Augsburg against France and led military campaigns, including the successful siege of Bonn in 1689. Despite his opposition to France, he admired French culture and modeled his court after that of Louis XIV.Frederick sought to elevate his title from Elector to King. At that time, Germanic law prohibited kingdoms within the Holy Roman Empire, except for Bohemia. He negotiated with Emperor Leopold I, resulting in the Crown Treaty of 16 November 1700, which allowed him to declare Prussia a kingdom in exchange for military support against Louis XIV during the War of the Spanish Succession. Frederick crowned himself King in Prussia on 18 January 1701 in Königsberg, although the Polish–Lithuanian Commonwealth contested the legality of this coronation. To acknowledge historical ties to Poland, he referred to himself as 'King in Prussia' rather than 'King of Prussia.'Frederick sought international recognition for his title, gaining support from England, which sent an envoy to Berlin to acknowledge his kingship. He provided troops to England during the war, often withholding them until he received the desired ceremonial recognition. His royal authority was limited to Prussia, and he remained an elector under the Holy Roman Emperor in Brandenburg. However, by the time of his coronation, the emperor's influence over Brandenburg was nominal, and Frederick's realm began to be viewed as a kingdom.Frederick I was a patron of the arts and education, founding the Prussian Academy of Arts in Berlin in 1696 and the Academy of Sciences in 1700, although the latter was closed by his son for economic reasons. He appointed Jacob Paul von Gundling as a professor at the Berlin Knights Academy in 1705 and as historian at the Higher Herald's Office in 1706. Frederick I died on 25 February 1713 in Berlin and was interred in the Berlin Cathedral.Frederick I married three times. His first marriage was to Elizabeth Henrietta of Hesse-Kassel in 1679, with whom he had one daughter, Louise Dorothea, who died without issue. His second marriage was to Sophia Charlotte of Hanover, with whom he had two children: Frederick August, who died in infancy, and Frederick William I, who succeeded him. In 1708, he married Sophia Louise of Mecklenburg-Schwerin, who survived him but bore no children. He also had a long-term mistress, Catharina von Wartenberg, but remained devoted to his second wife.