White Castle was established by the Normans in the wake of the invasion of England in 1066, to protect the route from Wales to Hereford. Possibly commissioned by William fitz Osbern, the Earl of Hereford, it comprised three large earthworks with timber defences. In 1135, a major Welsh revolt took place and in response King Stephen brought together White Castle and its sister fortifications of Grosmont and Skenfrith to form a lordship known as the 'Three Castles', which continued to play a role in defending the region from Welsh attack for several centuries.
King John gave the castle to a powerful royal official, Hubert de Burgh, in 1201. Over the next few decades, it passed back and forth between several owners, as Hubert, the rival de Braose family, and the Crown took control of the property. During this period, White Castle was substantially rebuilt, with stone curtain walls, mural towers and gatehouses. In 1267 it was granted to Edmund, the Earl of Lancaster, and remained in the hands of the earldom, and later duchy, of Lancaster until 1825.
Edward I's conquest of Wales in 1282 removed much of White Castle's military utility, and by the 16th century it had fallen into disuse and ruin.
The castle is made up of a central inner ward, a crescent-shaped hornwork to the south, and an outer ward to the north, with its stonework constructed from red sandstone. The outer ward was originally much larger, extending around the castle further to the east, but only limited traces of these earthworks survive. It is now entered from the north-east although, prior to the 13th century, the castle 's entrance was originally on the south side. The historian Paul Remfry considers the castle to be 'a masterpiece of military engineering' for the period.
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.