Colmar was founded in the 9th century. This was the location where Charles the Fat held a diet in 884. Colmar was granted the status of a free imperial city of the Holy Roman Empire in 1226. In 1575, the city adopted the Protestant Reformation, long after the northern neighbours of Strasbourg and Sélestat. During the Thirty Years' War, the city was taken by the armies of Sweden in 1632, who held it for two years. The city was conquered by France under Louis XIV in 1673.
In 1679 (Treaties of Nijmegen) Colmar was ceded to France. With the rest of Alsace, Colmar was annexed by the newly formed German Empire in 1871 as a result of the Franco-Prussian War. It returned to France after World War I, was annexed by Nazi Germany in 1940, and then reverted to French control after the battle of the "Colmar Pocket" in 1945. Colmar has been continuously governed by conservative parties since 1947, the Popular Republican Movement (1947–1977), the Union for French Democracy (1977–1995) and the Union for a Popular Movement(since 1995), and has had only three mayors during that time.
The Colmar Treasure, hidden during the Black Death, was discovered here in 1863
