Xanten Cathedral (Xantener Dom) is considered the biggest cathedral between Cologne and the North sea. The cathedral owes its name to Victor of Xanten, a member of the Theban Legion who was supposedly executed in the 4th century in the amphitheater of Castra Vetera for refusing to sacrifice to the Roman gods. This Roman camp is near today's town of Birten. According to legend, Helena of Constantinople recovered the bones of Victor and his legion and erected a chapel in their honour. During a modern excavation the existence of a 4th-century cella memoriae was discovered; however, it was determined that it had not been erected for Victor but for two other male corpses that were placed in the crypt at a later date.
The cornerstone of the cathedral was laid in 1263 by Friedrich and Konrad von Hochstaden. Construction lasted 281 years and was finally finished with the dedication of the Holy Spirit Chapel in 1544. The cathedral contains a five-aisle nave built in the Gothic style. In contrast to many other cathedrals of the period, St. Victor's lacks an ambulatory. Instead a twin pair of chapels is connected to the choir similar to that seen at the Church of Our Lady in Trier. Along with the monasterial library of the Cathedral houses one of the most important religious libraries of the Lower Rhine.
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.