 Some traditions of Roman architecture also survived in Byzantine architecture with the 6th-century octagonal Byzantine Basilica of San Vitale in Ravenna being the inspiration for the greatest building of the Dark Ages in Europe, the Emperor Charlemagne's Palatine Chapel, Aachen, Germany, built around the year AD 800.Dating shortly after the Palatine Chapel is a remarkable 9th-century Swiss manuscript known as the Plan of Saint Gall and showing a very detailed plan of a monastic complex, with all its various monastic buildings and their functions labelled.The largest building is the church, the plan of which is distinctly Germanic, having an apse at both ends, an arrangement not generally seen elsewhere.