The town hall was originally built as a church in the 15th Century. During the reformation in the 16th Century Gustav Vasa gave the church to the people of Arboga and its new purpose was to be the town hall. However the king used the house as his own private residence instead. His daughter, Cecilia, Countess of Arboga, also lived here in 1570. From 1640 to the present day Arboga’s town council has had offices here. The present appearance dates from the renovation made in 1725-1759.
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.