Sigtuna during the early Middle Ages, in 1187, were Estonians.
In the 1st centuries AD, political and administrative subdivisions began to emerge in Estonia. Two larger subdivisions appeared: the province (Estonian: kihelkond) and the land (Estonian: maakond). The province comprised several elderships or villages. Nearly all provinces had at least one fortress. The defense of the local area was directed by the highest official, the king or elder. By the 13th century the following major lands had developed in Estonia: Revala, Harjumaa, Saaremaa, Hiiumaa, Läänemaa, Alempois, Sakala, Ugandi, Jogentagana, Soopoolitse, Vaiga, Mõhu, Nurmekund, Järvamaa and Virumaa.
Estonia retained a pagan religion centred around a deity called Tharapita. The Chronicle of Henry of Livonia mentions Tharapita as the superior god of Oeselians (inhabitants of Saaremaa island), also well known to Vironian tribes in northern Estonia.
Viking Age
The Oeselians or Osilians (Estonian saarlased; singular: saarlane) were a historical subdivision of Estonians inhabiting Saaremaa (Danish: Øsel; German: Ösel; Swedish: Ösel), an Estonian island in the Baltic Sea. They are first thought to be mentioned as early as the 2nd century BC in Ptolemy's Geography III. The Oeselians were known in the Old Norse Icelandic Sagas and in Heimskringla as Víkingr frá Esthland (English: Estonian Vikings). Their sailing vessels were called pirate ships by Henry of Livonia in his Latin chronicles from the beginning of the 13th century.
Perhaps the most renowned raid by Oeselian pirates occurred in 1187, with the attack on the Swedish town of Sigtuna by Finnic raiders from Couronia and Oesel. Among the casualties of this raid was the Swedish archbishop Johannes. The city remained occupied for some time, contributing to the decline as a center of commerce in the 13th century in favor of Uppsala, Visby, Kalmar and Stockholm.
The Livonian Chronicle describes the
