Belarus has been inhabited since prehistoric times, and the first
recorded settlements date back to the 6th century AD. The princes of
Kiev ruled Belarus until the invasion of the Mongols in 1240, when
most of its towns were destroyed.
 
The region came under the control of powerful Lithuanians and, in
1386, under the Lithuanian-Polish Jagiellonian Dynasty. For centuries,
the Poles and the Muscovites struggled bitterly over Belarus. In 1772,
Catherine the Great gained control over part of the country, and, by
1795, Russia ruled all of Belarus.
 
During the 19th and 20th centuries, the country again became a
European battleground. Napoleon passed through Belarus--and fought
there--in 1812, and the Germans fought the Soviets on Belarusian
territory in World War I. Although a Soviet Socialist Republic was
proclaimed in January 1919, fighting with Poland continued until 1921.
 
Belarus suffered heavy losses in World War II, when some 2.2 million
inhabitants perished. The postwar period saw a significant rebirth--
especially in the economic sphere. On August 25, 1991, Belarus
declared its independence from the Soviet Union.

source: U.S. State Department Background Notes 1996