Jistrum church was built in the 13th century, the tower is a little older and dates from c. 1230. The church was once a Roman Catholic church dedicated to Saint Peter but was stripped of the Saints statues and painted/decorated walls in one week in 1581 during the Protestant Reformation and became a Protestant church. It is a well preserved and complete 13th century Romanesque church built of red brick.
The church has a gabled roof. On the corners of the nave is a buttress in brickwork, the outer walls are on the upper side decorated with so called keper friezen. The north wall has two Romanesque windows located in the higher zone of the wall, and the lower zone has two closed entrances with brick. The southern wall shows a similar layout but has two large lancet windows build in it, with one small Romanesque window at the tower side. The choir has five regular placed Romanesque windows and the nave is covered with a Romanesque-Gothic domevault. In each bay eight ribs come together in a ring. In the west bay the ribs are squire shaped. During a renovation two hagioscopes were discovered and restored. These windows are also known as leprozenruitjes (windows for people with leprosy).
The wooden pulpit from the third quarter of the 17th century is located against the north wall where the choir and bay meet.
Most of the Frisian churches have a golden rooster as weather vane, but on the 20.5 meters high tower of the church a horse is seen. The golden rooster is a symbol of Jesus Christ who breaks the power of the darkness, forgives sins and calls for a new day. The tower had also a rooster in the past, but it was blown of by the wind and could not be repaired. It was then replaced by a horse because it was cheaper. Apparently the price was more important than the symbolic value.
The original bell in the tower from 1759 was stolen by the Germans during World War II, the current bell dateing from 1949. In 2007, the renovation of the church started and the monumental Pipe organ from the other church in town was installed.
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.