Editing Northern Crusades (section)

===Wars against Saaremaa (1206–1261)===
The last Estonian county to hold out against the invaders was the island county of [[Saaremaa]] (Ösel), whose war fleets had raided Denmark and Sweden during the years of fighting against the German crusaders.

In 1206, a Danish army led by the king [[Valdemar II]] and [[Anders Sunesen|Andreas, the Bishop of Lund]] landed on Saaremaa and attempted to establish a stronghold without success. In 1216 the [[Livonian Brothers of the Sword]] and the bishop Theodorich joined forces and invaded Saaremaa over the frozen sea. In return, the [[Oeselians]] raided the territories in Latvia that were under German rule the following spring. In 1220, the Swedish army led by king [[John I of Sweden]] and the bishop [[Karl Magnusson (Bjälboätten)|Karl of Linköping]] conquered [[Lihula]] in [[Lääne County|Rotalia]] in Western Estonia. Oeselians attacked the Swedish stronghold the same year, conquered it and killed the entire Swedish garrison including the Bishop of Linköping.

In 1222, the Danish king [[Valdemar II]] attempted the second conquest of Saaremaa, this time establishing a stone fortress housing a strong garrison. The Danish stronghold was besieged and surrendered within five days, the Danish garrison returned to [[Tallinn|Revel]], leaving bishop [[Albert of Riga]]'s brother Theodoric, and few others, behind as hostages for peace. The castle was razed to the ground by the Oeselians.<ref>{{cite book |url=https://books.google.com/books?id=GNBNHgAACAAJ |title=The Baltic Crusade |first=William L. |last=Urban |publisher=Lithuanian Research and Studies Center |year=1994 |pages=113–114 |isbn=0-929700-10-4}}</ref>

A 20,000 strong army under Papal legate [[William of Modena]] crossed the frozen sea while the Saaremaa fleet was icebound, in January 1227. After the surrender of two major Oeselian strongholds, [[Muhu]] and [[Valjala]], the Oeselians formally accepted Christianity.

In 1236, after the defeat of the Livonian Brothers of the Sword in the [[Battle of Saule]], military action on Saaremaa broke out again. In 1261, warfare continued as the Oeselians had once more renounced Christianity and killed all the Germans on the island. A peace treaty was signed after the united forces of the [[Livonian Order]], the [[Bishopric of Ösel-Wiek]], and [[Danish Estonia]], including mainland Estonians and Latvians, defeated the Oeselians by conquering their stronghold at Kaarma. Soon thereafter, the [[Livonian Order]] established a stone fort at [[Pöide Parish|Pöide]].