The Estonians, an ancient people, originally came from a region just west of the Ural Mountains. Historical references to Estonia begin in the 1100's. At that time the region was divided into small pagan states. Beginning in 1202, an order of German crusading knights from Livonia (Latvia) joined with the Danes to conquer and Christianize the Estonians. By 1227 the Danes controlled northern Estonia; the Livonian Knights, southern Estonia. The Teutonic Knights, another German crusading order, gained control of southern Estonia in 1237 and later conquered all of Estonia.

The Teutonic Knights withdrew from Estonia in 1560. Sweden and Poland then fought for control of Estonia; in 1629, Sweden won and annexed the region. Peter I of Russia conquered Estonia in 1710, and in 1721 Sweden formally recognized Russian possession of the region.

An independent republic was proclaimed in 1918. The Soviet Union occupied Estonia in 1940, after charging that Estonia had violated an agreement by signing an alliance with Lithuania and Latvia. A puppet government voted to make the nation a union republic of the Soviet Union. Germany drove Soviet forces out in 1941, but they returned in 1944. The United States and several other nations refused to recognize the Communist regime.

Estonian nationalism heightened in the 1980's. During 1988–90, the Estonian parliament passed various laws intended to increase Estonia's autonomy. In 1991 rising nationalism throughout the union republics eroded the authority of the Soviet central government. Estonia declared independence in August. In September Estonia was granted independence and became a member of the United Nations. In 1994 Russian troops were withdrawn from Estonia. (Russian troops had been in Estonia since 1994.) In 2004, Estonia joined NATO.