In 748 Mondsee Abbey was founded by Odilo, Duke of Bavaria. The abbey tradition was that the first monks came from Monte Cassino in Italy. In 788, after the fall of Duke Tassilo III, Mondsee became an Imperial abbey and over the centuries acquired extensive property. Around 800 the Codex Millenarius, an illustrated Latin book of the Gospels was written at the abbey. In 831 King Louis the Pious gave the monastery to Regensburg Cathedral.
It was not until 1142 that it regained its independence, under Abbot Conrad II, otherwise Blessed Conrad of Mondsee. Conrad, formerly a monk of Siegburg Abbey, had been abbot of Mondsee since 1127, and was extremely successful in defending and regaining the rights and possessions of the monastery, to the extent that in 1145 he was murdered by a group of nobles at Oberwang nearby. He was venerated as a martyr and declared Blessed.
Conrad was succeeded as abbot by Blessed Walter of Mondsee (died 17 May 1158), long remembered as a model by the community for his exemplary striving after virtue. He was buried in St. Peter's chapel in the abbey church.
In 1506 possession of the Mondseeland passed from Bavaria to Austria. In 1514 Abbot Wolfgang Haberl established the abbey grammar school. After a period of decline during the Reformation and the consequent disturbances, the abbey entered a new period of prosperity. Under Abbot Bernhard Lidl (1727-73) and especially in connection with the celebration of the thousandth anniversary of the foundation, there was extensive re-building of the church and the monastic premises. From 1773 the abbot was Opportunus II Dunkl, who was the last abbot of Mondsee: in 1791 the abbey was dissolved by Emperor Leopold II.
During the Napoleonic period the Mondseeland reverted to Bavaria for a few years. During that time, in 1810, the Bavarian Field Marshal Prince Karl Philipp von Wrede acquired the abandoned monastery (along with the nearby abbeys of Suben and Gleink), and used it as a castle. Wrede remained the owner even after the return of the territory to Austria and significantly developed the locality, for example by the construction of roads and the establishment of local cheese production. In 1905, on the death of Princess Ignazia von Wrede, Mondsee passed to the Counts Almeida, whose descendants sold it in 1985.
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.