The division of Estonia’s territory into counties, rural municipalities, and cities has developed over the centuries and has been adapted from time to time according to the needs of the era.
The origins of Estonia’s administrative division date back to ancient times. The formation of the administrative division began with the ancient parishes, which are known from historical records to have existed as early as at the end of the twelfth century. Originally, a parish was a union of villages with inhabitants belonging to the same tribe and having common economic interests. The parish usually had a central stronghold and was led by an elder. At the beginning of the thirteenth century, there were 40–45 parishes in Estonia. In the thirteenth century, unions of adjacent parishes gave rise to the counties.
Eight counties and a few independent parishes developed in Estonia during that time. There were about 45 parishes in Estonia, which formed counties. The counties were Harjumaa, Järvamaa, Läänemaa, Rävala, Saaremaa, Sakala, Ugandi, and Virumaa. Alempois, Nurmekund, Mõhu, and Vaiga were independent parishes.