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:The Basilica of Santa Maria in Trastevere is one of the oldest churches of Rome. The basic floor plan and wall structure of the church date back to the 340s, and much of the structure to 1140-43. The first sanctuary was built in 221 and 227 by Pope Callixtus I and later completed by Pope Julius I.
The inscription on the episcopal throne states that this is the first church in Rome dedicated to Mary, mother of Jesus, although some claim that privilege belongs to the Basilica di Santa Maria Maggiore. A Christian house-church was founded here about 220 by Pope Saint Callixtus I (217-222) on the site of the Taberna meritoria, a refuge for retired soldiers. The area was made available for Christian use by Emperor Alexander Severus when he settled a dispute between the Christians and tavern-keepers.
The church underwent two restorations in the fifth and eighth centuries and in 1140-43 it was re-erected on its old foundations under Pope Innocent II.