The first church built in Hossmo was most likely a wooden one. Coffins found show that there was probably a church here already in the 11th century. The construction of that church has been linked to the royal court or a powerful local family. Hossmo is considered to have been the centre of a region in the late Iron Age or early Middle Ages. The church was probably built as a royal demesne or a church for a powerful leader.
However, in the conflict between Christianity and the old paganism, a wooden church was far too vulnerable, and was replaced by a stone church. This happened about 1120, and during the 13th century, the church was rebuilt with fortifications. Several written sources show that the church was used as garrison and flank defense for Kalmar during the Union conflicts in the early 16th century, Most of what we now see inside the church dates back to the 18th and 19th century. The belfry was completed in 1670.
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.