A maakond (county) is the biggest administrative subdivision. The county government (Maavalitsus) of each county is led by a county governor (Maavanem), who represents the national government at the regional level.
Governors are appointed by the Government of Estonia for a term of five years. Several changes were made to the borders of counties after Estonia became independent, most notably the formation of Valga County (from parts of Võru, Tartu and Viljandi counties) and Petseri County (area acquired from Russia with the 1920 Tartu Peace Treaty).
During the Soviet rule, Petseri County was annexed and ceded to the Russian SFSR in 1945 where it became one the districts of Pskov Oblast.
Counties were again re-established on 1 January 1990 in the borders of the Soviet-era districts. Because of the numerous differences between the current and historical (pre-1940, and sometimes pre-1918) layouts, the historical borders are still used in ethnology, representing cultural and linguistic differences better.
Estonia is divided into 15 counties (maakond). Each county is further divided into municipalities (omavalitsus), which is also the smallest administrative subdivision of Estonia.
There are two types of municipalities: an urban municipality – linn (town), and a rural municipality – vald (parish). There is no other status distinction between them.
Each municipality is a unit of self-government with its representative and executive bodies. The municipalities in Estonia cover the entire territory of the country.
A municipality may contain one or more populated places. Tallinn is divided into eight districts (linnaosa) with limited self-government (Haabersti, Kesklinn (centre), Kristiine, Lasnamäe, Mustamäe, Nõmme, Pirita and Põhja-Tallinn).
Municipalities range in size from Tallinn with 400,000 inhabitants to Ruhnu with as few as 60.
As over two-thirds of the municipalities have a population of under 3,000, many of them have found it advantageous to co-operate in providing services and carrying out administrative functions. There have also been calls for an administrative reform to merge smaller municipalities together.
As of March 2008, there are a total of 227 municipalities in Estonia, 33 of them being urban and 193 rural.