Visborg

thumb|Castle Wisborg in an early 17th-century drawing Visborg (also spelled Wisborg) was a medieval fortress located in the town of Visby on the Swedish island of Gotland. Several fortresses were built in Visby over the centuries. The last was the castle built by King Erik of Pomerania, ruler of Kalmar Union. The fortress served as Erik’s residence after his deposition and remained an important Danish stronghold until its destruction in 1679. Today, only fragments of its walls survive overlooking Visby’s harbor.

== History == The first known fortress in the southwest corner of Visby was built around 1310 by Duke Erik, son of King Magnus Ladulås of Sweden, during a conflict with his brothers over control of Sweden and Norway.thumb|right|200px|Model of the fortress, Visby. In 1398, forces of the Teutonic Order under Grand Master Konrad von Jungingen captured Gotland and destroyed the earlier Visby fortifications, ending the rule of the pirate group known as the Victual Brothers, who had used the town as their base.