The oldest record of church in Halikko is dated back to the year 1352. The wooden church was replaced probably approximately 1440. Original, two-aisle church was dedicated to St. Birgit. During the Reformation old chalk paintings were overpainted and church was left to dilapidate. Too small and dicky church was renovated and expanded in 1799 and again in 1813-1815. The old sacristy, weapons room and the tomb of famous noble family Horn were dismantled then. New tombs for Horns and another famous noble family Armfelt were added to the church.
According the legend, Henrik Olafsson the Graf of Åminne manor financed the construction of the Halikko Church, the Pertteli Church and the Chapel of Salo to pay the sins of his family. His father-in-law had murdered his wife and the seen a vision in which Jesus said that he must pay his sins.
Visby Cathedral (also known as St. Mary’s Church) is the only survived medieval church in Visby. It was originally built for German merchants and inaugurated in 1225. Around the year 1350 the church was enlarged and converted into a basilica. The two-storey magazine was also added then above the nave as a warehouse for merchants.
Following the Reformation, the church was transformed into a parish church for the town of Visby. All other churches were abandoned. Shortly after the Reformation, in 1572, Gotland was made into its own Diocese, and the church designated its cathedral.
There is not much left of the original interior. The font is made of local red marble in the 13th century. The pulpit was made in Lübeck in 1684. There are 400 graves under the church floor.