Aachen Cathedral (German: Aachener Dom), frequently referred to as the "Imperial Cathedral" (Kaiserdom) and known as the "Royal Church of St. Mary at Aachen" during the Middle Ages, is a Roman Catholic church in the city of Aachen in western Germany. The church is the oldest cathedral in northern Europe, and was consructed by order of the Emperor Charlemagne (Charles the Great), who was buried here after his death in 814. For 595 years, from 936 to 1531, the Aachen chapel was the church of coronation for 30 German kingsand 12 queens. The church is currently the episcopal seat of the Diocese of Aachen, so named in 1802.