According to archaeological finds, there was a Slavic settlement already in the 6th-7th century in Libušín. At the end of the 9th century, a gord was built here. The Church of Saint George was probably founded in the 10th century in the gord's area. In 1650 the church took its current Baroque shape. The area of Church of Saint George and remains of the gord include a wooden bell tower built in 1500.
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.