Ortenburg castle was erected in the late 11th century by ministeriales of the Bavarian Prince-Bishops of Freising, who then held large possessions in the Duchy of Carinthia. Their descendants began to call themselves Counts of Ortenburg. The castle is located on the northern slope of the Gailtal Alps overlooking the Drava valley.
Damaged by the 1348 Friuli earthquake, the significance of the castle diminuished after the extinction of the Ortenburgs in 1418. The estates were inherited by Count Hermann II of Celje and in 1456 finally seized by the Imperial House of Habsburg. In 1524 the comital title passed to Gabriel von Salamanca, who had his new residence, Porcia castle built in the nearby town of Spittal an der Drau.
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.