===Administrative-Political-Territorial Divisions===
The USSR was divided into fifteen union republics - the largest administrative and political units - officially known as Soviet republics or union republics. Theoretically they were independent countries; in practice they were controlled by the Kremlin. Nationality, size of the population, and location were the determinants for republic status. By far the largest and most important was the Russian Republic, containing about 51% of the population. In 1989 Russians made up over 51% of the Soviet population and were politically, economically and culturally the dominant nationality, there are more than 100 other nationality groups that make up Soviet society. Fourteen other major nationalities also have their own republics: in the European part are the [[Lithuania]]n, [[Latvia]]n, [[Estonia]]n, [[Belorussia]]n, [[Ukraine|Ukrainian]], and [[Moldavia]]n republics; the [[Georgia (country)|Georgia]]n, Azerbaydzhan, and [[Armenian]] republics occupy the Caucasus; and Soviet Central Asia is home to the Kazakh, Uzbek, Turkmen, Kirgiz, and Tadzhik republics.
The Soviet republics were subdivided into administrative subdivisions called autonomous republics, autonomous oblasts, autonomous okruga, kraia, or most often oblasts. These subdivisions made the country easier to manage and some served to recognize additional nationalities.