Aschaffenburg is a city in Bavaria, Germany. It is located on the right bank of the Main and its confluence with the narrow Aschaff river, near the foot of the Spessart. The city of Aschaffenburg is not included in the district of Aschaffenburg, but is its administrative seat. Population: 66,800 (1999). Aschaffenburg, called in the Middle Ages Aschafaburg, was originally a Roman settlement. Roman legions had their station here, and on the ruins of their castrum the Frankish mayors of the palace built a castle. Saint Boniface erected a chapel to Saint Martin, and founded a Benedictine monastery. A stone bridge over the Main was built by Archbishop Willigis in 989. Adalbert increased the importance the town in various ways about 1122. In 1292 a synod was held here, and in 1474 an imperial diet, preliminary to that of Vienna, in which the concordat was decided which has therefore sometimes called the Aschaffenburg Concordat. The town suffered greatly during the Thirty Years' War, being held in turn by the various belligerents. In 1842 - 1849, King Ludwig I of Bavaria built himself to the west of the town a country house, Pompejanum, so called from its being an imitation of the house of Castor and Pollux at Pompeii. In 1866 the Prussians inflicted a severe defeat on the Austrians in the neighbourhood. The principality of Aschaffenburg, deriving its name from the city, comprehended an area of 1694 km?. It formed part the electorate of Mainz, and in 1803 was made over to the chancellor, Archbishop Charles of Dalberg. In 1806 it was annexed to the grand duchy of Frankfurt; and in 1814 was transferred to Bavaria, in virtue of a treaty concluded between that power and Austria. Within Lower Franconia, it now forms a part of the Bundesland of Bavaria. Its chief buildings are the Schloss Johannisburg, built (1605 - 1614) by Archbishop Schweikard von Kronberg, which contains a library with a number of incunabula, a collection of engravings and paintings; the Stiftskirche, or cathedral, founded in 974 by Otto of Bavaria, but dating in the main from the early 12th century on, in which are preserved various monuments by e Vischers, a sarcophagus with the relics of Saint Margaret, and a famous painting by Matthias Gr?d; the Capuchin hospital; a theatre, which was formerly a house of the Teutonic order; and several mansions of the nobility. The graves of Clemens Brentano and his brother Christian Brentano (died 1851) and that of Wilhelm Heinse are on the Altstadtfriedhof.