Tanum church was probably built between 1100-1130 and enlarged in the early 1700s. The restoration took place in 1900s. In 1674, the Krefting family built a sacristy with burial chambers beneath it on the north side of the chancel. However, this soon became too small, and in 1713 a larger burial chapel was built on the north side of the church, wall to wall with the sacristy. In total, around 40 members of the family were laid to rest in these two tombs. The church was expanded in 1722 and restored in the 1970s.
The richly decorated interior is well-preserved. There are unique 14th century mural paintings. A bell in the tower and two Gothic sculptures are preserved from the Middle Ages. The altarpiece you find in the church today is from 1631, and the font from the beginning of the 1800s.
Tanum church has been a popular subject for many artists. Harriet Backer immortalized the interior of the old Tanum church several times. The most famous painting is 'Baptism in Tanum Church' (Barnedåp i Tanum kirke) from 1892. You can see the painting in The National Gallery (Nasjonalgalleriet) in Oslo.
The church and cemetery have been located to the ancient pagan worship site. There are Iron age burial mounds near the church.
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.