St Mary's Church is dated mainly to the 14th century, though significant alterations were added in the 16th century. The tower dates to the latter period. The church was extensively renovated by J. Pritchard and J.P. Seddon in 1860. The eastern stained class windows were added by Morris & Co. P.S. Webb was responsible for the patterns while the figures are the work of P.P. Marshall. Among the depictions on these windows are Christ saving Peter from drowning in the sea, Christ miraculously curing a woman, and Thomas the Doubter. The octagonal font dates to the 19th century, while the pulpit was installed in 1942.
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.