Visborg (a.k.a. Wisborg) Castle was built here by Eric of Pomerania, the ruler of the Kalmar Union, also known as Eric III as King of Norway (1389–1442), Eric VII as King of Denmark (1396–1439) and Eric XIII as King of Sweden (1396–1434, 1436–39). Later, in all three countries he became more commonly known as Eric of Pomerania (Erik av Pommern in Swedish). According to the Visby Franciscans' diary, he laid the first foundation stone of the Visborg castle on August 1, 1411 after having bought back the island from the Teutonic Order in 1408.
Sadly, only vague remains of a ruin represent today what once was a magnificent castle complex, a fortress. The castle was built as an irregular square and occupied the territory between the southern wall, Visborgsgatan, Kommendantbacken, Piparhålstrappan and the harbor area.
After King Eric lost the royal title, the castle became his residence from where he began his pirate activities in the Baltic Sea.
And then a long period of warfare between the kings of Denmark and Sweden began over who would once again rule over the three kingdoms of the Kalmar Union. With tensions rising, Gotland became an immediate point of conflict. In 1448, King Charles of Sweden launched an invasion of the island and was able to secure all but Visby because of the fortifications at Visborg, still inhabited by the deposed King Eric. Soon after, Eric made a deal with Christian I in which he agreed to cede Gotland to the Danes and renounce his claims to the throne in return for safe passage to Pomerania. Christian agreed and in 1449 the Danish army sneaked in under cover of darkness. As the Danes moved in, the Swedes evacuated the island. As promised Eric was given safe passage to Pomerania where he ruled the Duchy of Stolp as Eric I until his death in 1459.
Denmark retained continuous rule of the island for almost 200 years until a peace treaty was signed in 1645 making Gotland a part of Sweden again, for the next 30 years. Denmark gained it back in 1676 but three years later signed another peace treaty with Sweden in which they agreed to return Gotland. As the Danish soldiers were leaving Visby in 1679, they blew up the castle of Visborg.
After Gotland was taken over by Sweden, Governor General Johan Cedercrantz had a couple of lime kilns built at the ruins and most of the ruins were converted into quicklime which was used for the reconstruction of Stockholm Castle (
https://reveal.world/story/strangely-large-palace), as well as some public buildings in Karlskrona. The rough wall sections that now remain in the southwest corner are remains of the Frustugan and the southern castle wall. Otherwise, the area was allowed to fall into disrepair and it was used as pasture for the townspeople's livestock. In the middle of the 18th century, the blocks around the current Visborgsgatan began to be built up.
Photo: Early 17th-century drawing of Wisborg (Visborg) Castle in Gotland, Sweden, today in ruins. Author unknown.
