Estuna Church dates from the early 13th century or possibly the late 12th century. The structure of the building indicates that a tower was initially planned for the eastern end of the church but never built. It may have been intended as a defensive tower which became redundant as times became more peaceful as the Middle Ages progressed in Sweden.
The church has been rebuilt and expanded several times. During a renovation of the altar in 1733 a patch of parchment was discovered that noted the date of a re-inauguration of the church to 1298. This was probably done in connection with an enlargement of the church towards the west. The church porch was added during the 15th century. During a renovation in the 20th century, medieval frescoes were discovered and uncovered. Among the church furnishings, most date from the 18th century. The baptismal font is however older, from the 13th century. The elaborate crucifix was donated to the church in 1783 and made in Rome.
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.