Ösel

Ösel-Wiek was a Livonian prince-bishopric encompassing the Estonian islands of Ösel and Dagö and the mainland region of Wiek. Founded in 1228, it was ruled in 1337 by Bishop James.

After the St. George’s Night uprising in 1343, the Livonian Order suppressed Ösel’s autonomy. During the Livonian War the last bishop, Johannes von Münchhausen, sold the bishopric to Denmark in 1560; Duke Magnus of Holstein abolished the see in 1567. Wiek passed to Poland-Lithuania, while Ösel remained Danish until Sweden acquired it by the 1645 Treaty of Brömsebro.