Saaremaa is the largest island in Estonia, measuring 2,673 km². The main island of Saare County, it is located in the Baltic Sea, south of Hiiumaa island, and belongs to the West Estonian Archipelago. The capital of the island is Kuressaare, which has about 15,000 inhabitants; the whole island has over 39,000 inhabitants.
According to archaeological finds, the territory of Saaremaa has been inhabited from at least 5,000 years BCE. Sagas talk about numerous skirmishes between islanders and Vikings. Saaremaa was the wealthiest county of ancient Estonia and the home of notorious Estonian pirates, sometimes called the Eastern Vikings. The Chronicle of Henry of Livonia describes a fleet of sixteen ships and five hundred Osilians ravaging the area that is now southern Sweden, then belonging to Denmark. In 1206, King Valdemar II of Denmark built a fortress on the island but found no volunteers to man it. The Danes burned it themselves and left.
Probably around 1000 Gunnar Hámundarson from Iceland was in wiking at Eysýsla (Saaremaa). There he obtained his famous atgeir, by taking it from a man named Hallgrímur. Njáls saga tells the following:
«Thence they held on south to Denmark and thence east to Smálönd and had victory wherever they went. They did not come back in autumn. The next summer they held on to Rafala (Tallinn) and fell in there with sea-rovers, and fought at once, and won the fight. After that they steered east to Eysýsla (Saaremaa) and lay there somewhile under a ness. There they saw a man coming down from the ness above them; Gunnar went on shore to meet the man, and they had a talk. Gunnar asked him his name, and he said it was Tófi. Gunnar asked again what he wanted. «Thee I want to see,» says the man. » Two warships lie on the other side under the ness, and I will tell thee who command them: two brothers are the captains — one’s name is Hallgrímur, and the other’s Kolskeggur. I know them to be mighty men of war; and I know too that they have such good weapons that the like are not to be had. Hallgrímur has an atgeir which he had made by seething-spells; and this is what the spells say, that no weapon shall give him his death-blow save that atgeir. That thing follows it too that it is known at once when a man is to be slain with that atgeir, for something sings in it so loudly that it may be heard along way off — such a strong nature has that atgeir in it.»
In 1227, Saaremaa was conquered by the Livonian Brothers of the Sword during the Livonian Crusade, but remained a hotbed of Estonian resistance. The crusaders founded the Bishopric of Ösel-Wiek there. When the Order was defeated by the Lithuanian army in the Battle of Saule in 1236, the Saaremaa islanders rebelled. The conflict was ended by a treaty that was signed by the Osilians and the Master of the Order. In the following year, the Sword-Brothers were absorbed into the Teutonic Order.
Most of Saaremaa was ruled directly by the Bishopric of Ösel-Wiek, while some parts were enfeoffed to the Livonian Order. In 1559, the bishopric and Saaremaa were sold to Denmark, becoming part of Danish Estonia. From 1570 until 1645 the entire island was under Danish possession.
In 1645, Saaremaa was ceded from Denmark to Sweden by the Treaty of Brömsebro. In 1721, along with the rest of Livonia, Saaremaa (then known by its Swedish name of Ösel) was ceded to the Russian Empire by the Treaty of Nystad, becoming a part of the Governorate of Livonia. In 1840 the first spa opened in Kuressaare (then known as Arensburg), and the town became a resort for Russians and Baltic Germans.
In World War I, the Estonian islands were conquered by Imperial German Army in October 1917 and occupied (Operation Albion) until the end of hostilities. Estonia became independent after the October Revolution and the collapse of the Russian Empire. As a result of the Molotov-Ribbentrop Pact, the new state was incorporated into the Soviet Union in June 1940 as the Estonian Soviet Socialist Republic. Most of the Baltic German population of the island was evacuated to Germany following the Pact. The island was occupied by Nazi Germany in 1941 (Operation Beowulf); German troops remained there until expelled by the Red Army in the Moonzund Landing Operation in October and November 1944. In 1946, Saaremaa was declared a restricted zone, closed to foreigners and to most mainland Estonians. It remained a restricted area until 1989.
Estonian independence was regained on 20 August 1991, in the dissolution of the Soviet Union.