By the end of the 12th century, Latvia was increasingly visited by merchants from Western Europe, particularly Germans, traveling along the Daugava River to trade with Kievan Rus'. Many of these traders brought Christian missionaries to convert the Baltic and Finnic peoples, including the Livonians, who lived along the river’s shores. However, the locals resisted these efforts, especially the rite of baptism, prompting Pope Celestine III in 1195 to call for a crusade to forcibly convert the pagans.
In the early 1180s, Saint Meinhard began preaching among the Livonians, but his mission failed to gain widespread acceptance. His successor, Bishop Berthold of Hanover, also struggled to convert the population and was killed by Livonians in 1198. In 1199, Berthold’s replacement, Bishop Albert of Riga, arrived with the backing of military reinforcements. Albert spent nearly 30 years leading campaigns to subjugate the local tribes, establishing German dominance in the region. In 1201, he founded the city of Riga, which grew into a major Baltic port and became the center of German power.
To support the conquest, the Order of the Livonian Brothers of the Sword was established in 1202. The crusaders quickly subdued the Livonians by 1207, converting them and placing their territory under German control. At the same time, Terra Mariana, a Christian state encompassing modern Latvia and Estonia, was declared under the direct authority of the Pope. By 1214, most of the Latgalian territories, including the Principality of Jersika, had also been conquered. Jersika’s ruler, Visvaldis, was defeated and forced to accept German rule, retaining only part of his land as a vassal.
Medieval Livonia. © Termer
Over the next decades, the crusaders systematically expanded their conquests. By 1224, the Latgalian principalities of Tālava and Adzele were partitioned between the Bishop of Riga and the Brothers of the Sword. Meanwhile, the Curonians and Semigallians fiercely resisted German incursions. The Curonians and the Semigallians, led by chiefs like Viestards, allied with Lithuanians to oppose the crusaders.
In 1236, the crusaders suffered a catastrophic defeat at the hands of Samogitians and Semigallians at the Battle of Saule. The loss nearly annihilated the Brothers of the Sword, forcing them to merge with the more powerful Teutonic Order, becoming the Livonian Order in 1237. Despite their setbacks, the crusaders resumed their campaigns. By 1245, much of Courland had been conquered, with fortresses such as Kuldīga serving as centers of German control.
The Semigallians continued their resistance longer than most tribes. In 1279, under Duke Nameisis, they launched a major rebellion and allied with Lithuanian forces to defeat the Livonian Order at the Battle of Aizkraukle. The Semigallians even attempted to capture Riga in 1280, though they were ultimately unsuccessful. German forces responded by besieging Turaida Castle and building new strongholds like Heiligenberg to tighten their grip. The final Semigallian hillforts fell in 1289–1290, and many Semigallian warriors fled to Lithuania, marking the end of their independence.
By the close of the 13th century, all of the major Baltic tribes in Latvia—Livonians, Latgalians, Selonians, Curonians, and Semigallians—had been conquered. German settlers imposed new political and economic structures, integrating the region into the broader Christian world under German rule. The conquest of Latvia was part of the larger Northern Crusades, which aimed to Christianize the pagan peoples around the Baltic Sea. Although the campaigns brought Christianity and trade networks to the region, they also marked the end of the autonomous tribal societies and the beginning of centuries of German dominance in Latvia