Rēzekne Castle served as a base of the local Livonian order landlords until the 16th century and also as the main military support base for battles against Russians and Lithuanians. Archeological excavations reveal that between the 9th and 12th centuries a Latgalian wooden fortress was situated in the place where the castle ruins now stand. It is unknown when the Latgalian fortress was destroyed, however in 1285 the master of the Livonian Order Vilhelms Šurborgs built a stone fortress on the Rositten stone hill. The fortress consisted of a two-story brick and stone castle with a three-storey towers and thick brick walls, functioning as the administrative seat of Rezekne.
The castle was ravaged and rebuilt many times. Between 1577 and 1579, it was occupied by Czar Ivan IV Vasilyevich, and after the war it became part of the Duchy of Livonia. During the Polish-Swedish War in 1601, and again from 1625 to 1626, the Rezekne castle was occupied by the Swedish army, during the Second Northern War. The battle took place in 1656, during which the Rezekne castle was finally destroyed as the Swedish troops managed to defeat the much larger Russian forces. In 1660 it was reinstated, but the castle had lost its former military importance. From 1712 it was left in ruins. Today, fragments of the stone walls and the foundation can be seen on the ancient castle hill.
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.