The Parish Church of St Clement's origins lie with a privately owned wooded chapel which is thought to have been destroyed during the Norman raids. Construction of the stone church began around the year 911, starting with a chapel which is now the nave. The church became a parish church no later than 1067, because it is known that Duke William II of Normandy granted half the tithes of the church to the Abbey of Montivilliers in Upper Normandy. Only parish churches were permitted to collect tithes.
In the 15th century the church was considerably enlarged by the addition of a chancel and transepts, giving it the usual cruciform shape of most Christian churches. It has been possible to ascertain the approximate date for these enlargements and alterations from the Payn Arms (the three trefoils) in the chancel. The Payns were the Seigneurs of Samares during the 15th century. Also from this period are the gargoyles on the East outside wall, and the murals or frescoes inside the church. When the church was enlarged, the roof was raised and constructed in stone. The line of this may still be observed on the tower arch and buttresses were also constructed to support the weight.
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.