A great abbey church named Belli Locus dedicated to the Holy Sepulchre was founded in the early 11th century by Fulk Nerra, Count of Anjou, who is buried in the chancel. In 1011 Pope Sergius IV donated some relics of Saints Chrysanthus and Daria and Fulk himself a piece of the Holy Sepulchre he stole from his visit to Jerusalem to the abbey. The pope settled a dispute over the abbey's consecration with the Archbishop of Tours by himself sending a legate to consecrate it. The abbey was closed down in 1791.
References: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.