St. Lawrence's Church has a long and complicated history that goes back to sometime around the end of the 13th century. It is one of few medieval churches in Östergötland built entirely in brick, a circumstance which may be connected to there being a large number of German merchants active in Söderköping at the time, and it remains a fine Swedish example of Brick Gothic. The original church had the form of a basilica with a central nave and two aisles.
During a city fire in 1494 the church was damaged and subsequently rebuilt. An external belfry was erected in the 1580s. During its history, it has been reconstructed, renovated and altered on several occasions, but retains much of its medieval form and look. Externally, the church is dominated by its red brick façade, interspersed with blind arches and supported by brick buttresses. As it has no protruding apse, both the west and the east end of the church is marked by straight façades that end in crow-stepped gables. On the external wall of the vestry, St. Lawrence is depicted. During a renovation in 1965, an immured runestone was discovered and laid bare in one of the walls.
The interior today is a typical hall church, dominated by white-washed vaulting. Remains of medieval fresco painting has been laid bare during 20th-century restorations. The church also contains some noteworthy inventories, such as a late medieval altarpiece (possibly French), a triumphal crucifix (possibly made in Vadstena circa 1400), a processional crucifix from the 13th century and several medieval carved wooden statuettes of saints.
The church has been the venue for royal coronations in Sweden on two occasions. The first time was when Hedwig of Holstein, wife of Magnus III of Sweden, was crowned Queen of Sweden on 29 June 1281. The second was when Birger Magnusson and Martha of Denmark were crowned King and Queen of Sweden in the church in 1302.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.