Montebourg Abbey was probably established by William the Conqueror after the invasion to England (1066). The exact date is unknown, but it was before William's death in 1087. The abbey got lot of donations from the Dukes of Normandy and Kings of England until the 1180s. It had a large land property even in the southern England and the abbey grew up quickly in the 12th century.
The abbey suffered damages in the Hundred Years' War, but it was renovated in the mid-15th century. In 1562 Huguenots looted the abbey during the Frencg Wars of Religion. The first school in Montebourg was established in 1585 and in the 18th century it was used as Catholic poor house and rest home. But soon after the Great Revolution caused the decline of Montebourg Abbey. It was reduced to the state and monastic buildings were partially demolished. In 1842, the Vicar General of Coutances acquired what was by then only an enclosure of ruins, and set it up for the Brothers of Mercy, which he had just formed in order to promote Catholic education in the countryside. From there, the brothers have continued their work.
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.