The church was built in Romanesque style during the 13th century, but underwent some changes during the 19th century. The southern portal was then removed, and the spire of the tower changed from its original, pointed design to its presently visible crow-stepped design, traditionally not found on churches of Gotland. The altarpiece, pulpit and pews date from the 17th century. An oil painting by Fredrik Westin that hangs in the church is a gift from Princess Eugenie of Sweden and Norway, who spent several summers in the countryside near the church.References:
First record of Kastelholma (or Kastelholm) castle is from the year 1388 in the contract of Queen Margaret I of Denmark, where a large portion of the inheritance of Bo Jonsson Grip was given to the queen. The heyday of the castle was in the 15th and 16th centuries when it was administrated by Danish and Swedish kings and stewards of the realms. Kastelhoma was expanded and enhanced several times.
In the end of 16th century castle was owned by the previous queen Catherine Jagellon (Stenbock), an enemy of the King of Sweden Eric XIV. King Eric conquered Kastelholma in 1599 and all defending officers were taken to Turku and executed. The castle was damaged under the siege and it took 30 years to renovate it.
In 1634 Åland was joined with the County of Åbo and Björneborg and Kastelholma lost its administrative status.