Saint-Sever-Calvados Abbey was founded by Guillaume Sanche, the lord of Gascony in the late 10th century. According to the monastic chronicles, this was as the result of a vow he made after the battle of Taller, in Gascony, in which he defeated the Vikings (982). In 1060, after a fire, the abbey was reconstructed on the model of Cluny under the direction of the abbot Gregori de Montaner. The Saint-Sever Beatus was the work of monks working under the direction of the same abbot; Abbot Gregori held the post from 1028 to 1072.
Today there is a Gothic abbey church and a bell-tower on opposite sides of the square. There were centuries when people built, and others when they did not hesitate to split a building in two. The choir was a Benedictine enclosure, with the other half open to the people. However, except for the tower, this second half of the church has not been survived. The French Revolution drove the monks away and the abbey was closed.
References:The Church of St Donatus name refers to Donatus of Zadar, who began construction on this church in the 9th century and ended it on the northeastern part of the Roman forum. It is the largest Pre-Romanesque building in Croatia.
The beginning of the building of the church was placed to the second half of the 8th century, and it is supposed to have been completed in the 9th century. The Zadar bishop and diplomat Donat (8th and 9th centuries) is credited with the building of the church. He led the representations of the Dalmatian cities to Constantinople and Charles the Great, which is why this church bears slight resemblance to Charlemagne's court chapels, especially the one in Aachen, and also to the Basilica of San Vitale in Ravenna. It belongs to the Pre-Romanesque architectural period.
The circular church, formerly domed, is 27 m high and is characterised by simplicity and technical primitivism.