Aachen Cathedral cupola, Aachen, Germany, Unesco World Heritage Site. - stock photo

Aachen Cathedral cupola, Aachen, North Rhine Westphalia, Germany, Unesco World Heritage Site. Aachen Cathedral, frequently referred to as the "Imperial Cathedral" (in German: Kaiserdom), is a Roman Catholic church in Aachen, Germany. The church is the oldest cathedral in northern Europe and was known as the "Royal Church of St. Mary at Aachen" during the Middle Ages. For 600 years, from 936 to 1531, the Aachen chapel was the church of coronation for 30 German kings and 12 queens. Charles the Great (Charlemagne) began the construction of the Palatine Chapel around 796, along with the building of the rest of the palace structures. He was also buried here in Aachen cathedral in 814. In 1215 Emperor Frederick II re-interred him in a casket made of gold and silver which can still be seen. In the 14th and 15th centuries, Gothic additions were added to the church, including the choir in 1355. The core of the cathedral is the Carolingian Palatine Chapel, which is notably small in comparison to the later additions. A cupola, several other chapels and a steeple were also constructed at later dates. In 1978, it was one of the first 12 items to make the entry into the UNESCO list of world heritage sites, as the first German and one of the first three European historical ensembles.