A Roman town founded in the 1st cent. A.D., Frankfurt became (8th cent.) a royal residence under Charlemagne. After the Treaty of Verdun (843) it was briefly the capital of the kingdom of the Eastern Franks (i.e., Germany). It prospered as a commercial center and held annual fairs (first mentioned 1240) that drew merchants from all of Europe. Frankfurt was designated in the Golden Bull (1356) of Emperor Charles IV as the seat of the imperial elections, which took place in the chapel of the Church of St. Bartholomew. It was made a free imperial city in 1372.
After the emperors ceased to be crowned by the popes, the coronation ceremonies took place (1562–1792) at Frankfurt. The emperors-elect, after being crowned at St. Bartholomew's by the archbishop-elector of Mainz, proceeded with much pageantry to a banquet in the city hall, called Römer [Ger., = Romans] because the emperors-elect were crowned kings of the Romans. The coronation (1764) of Joseph II has been described in the autobiography of the writer Goethe, a native of Frankfurt.
Frankfurt accepted the Reformation in 1530, and was a member of the Schmalkaldic League. It was occupied many times in the wars of the 17th and 18th cent. Frankfurt was the original home of the Rothschilds, who, along with other Jewish merchants and bankers, played a leading role in the economic growth of the city (especially after 1700). After the dissolution (1806) of the Holy Roman Empire, Frankfurt was included in the ecclesiastic principality of Regensburg and Aschaffenburg, created by Napoleon I for Karl Theodor von Dalberg. The principality was converted in 1810 into the grand duchy of Frankfurt, also under Dalberg.
The Congress of Vienna (1814–15) restored Frankfurt to the status of a free city and made it the seat of the diet of the German Confederation. The Frankfurt Parliament, the first German national assembly, met there in 1848–49. Having sided with Austria in the Austro-Prussian War of 1866, Frankfurt was annexed by Prussia. In 1871 the Treaty of Frankfurt, which ended the Franco-Prussian War, was signed there. The city was heavily damaged in World War II, but after 1945 many of its historic landmarks were restored and numerous modern structures were built.