Ratisbon (Ger. Regensburg; anc. Reginum; mediaeval Lat. Ratisbona), a city of Bavaria, capital of the united district of the Upper Palatinate and Ratisbon, on the right bank of the Danube, opposite its junction with the Regen, 65 m. N. N. E. of Munich; pop. in 1871, 29,224, including about 6,000 Protestants, the rest being chiefly Catholics. It is a city of great antiquity, having crooked streets and tall, quaint houses with gable roofs, and intervening lofty towers. The restoration of the cathedral, founded about 1275, was completed in 1875; it has a richly sculptured portal, and is one of the grandest Gothic structures in Germany. The abbey of Emmeran, dating from 652, and improved by Charlemagne, consists of a vast pile of buildings, including the half ruined church with the shrine of St. Emmeran, the patron saint of the city; the cloisters have been embellished and enlarged by their present owner, Prince Thurn and Taxis. The Bischofshof, once the residence of German emperors, and where Maximilian II. died, is now a brewery.

The city has a town hall with interesting historical associations, an observatory, a lyceum, a gymnasium, an ecclesiastical seminary, an institution for the deaf and dumb, a public library, a well endowed hospital, and a fine promenade (Fürstengarten) at the rear of the Thurn and Taxis palace, with a monument of Kepler, who is buried in the Protestant cemetery. The most celebrated building in the vicinity of Ratisbon is the Walhalla, the Bavarian pantheon, at Donaustauf; it consists of a Doric marble temple after the model of the Parthenon of Athens, begun in 1816 by Klenze for the crown prince, afterward King Louis I., and opened in 1841. The Danube is spanned in Ratisbon by a stone bridge nearly 1,500 ft. long. The shipping trade chiefly consists of timber, grain, and salt, of which Ratisbon is the principal depot. Gold, silver, steel, tin, and other wares are made, and there are many breweries and distilleries. - Under the Romans Ratisbon was an important frontier fortress of Vindelicia. Subsequently it became a commercial centre, and in the 6th century the capital of Bavarian dukes. The important bishopric of Ratisbon was established in the 8th century. In the 12th century it was made a free imperial city.

In 1633-'4 it was successively taken by Maximilian of Bavaria, Bernard of Weimar, and the imperial troops. From 1663 to 1806 it was almost continually the seat of the German imperial diet. Under Charles Dalberg, elector of Mentz, the city and the see of Ratisbon formed together a principality from 1803 to 1810, when both were incorporated with the kingdom of Bavaria.