Between the sixth and the twelfth centuries, what is now known as Belarus was settled by the Slavs, who still dominate the country. The Early East Slavs gradually came into contact with the Varangians and were organized by them under the state of Kievan Rus’.

In the thirteenth century, several of the separate Ruthenian principalities were badly affected by a Mongol invasion. Later, parts of Rus were swallowed up by the Grand Duchy of Lithuania. Most of its population was ethnically slavonic. Slavonic lands enjoyed limited autonomy within Lithuanian state. Sometimes it is wrongly supposed that Belarusian was the official language of the state, because Latin, Old Russian (Ruthenian) and Polish were used side by side in state affairs. Belarusian language was born only in a middle of 19th century when Russian speakers in modern day Belarusian territory were subject to a heavy Polish cultural influence. At the beginning of 17th century Old Russian language was banned in Lithuania and replaced by Polish which was dominant for centuries already. Therefore the use of Old Russian (Old Slavonic-Ruthenian) was allowed in Ruthenian autonomies (principalities). Belarusian lands were easily incorporated into the Duchy within the next one hundred years, because of the strength of Lithuania and the threat of Mongols on modern day Belarusian lands. During this time, the Duchy was involved with battles between different forces. One of the major battles was between the Duchy and the Teutonic Knights at the Battle of Grunwald in 1410. The Duchy won the battle and the victory allowed the Duchy to control the North-western borders of Eastern Europe. Other miltary battles took place between the Duchy and the Mongols and the Turks, resulting in military victories for the Duchy. By the fifteenth century, the Grand Duchy of Lithuania stretched across much of Eastern Europe, spanning from the Baltic Sea to the Black Sea.

On February 2, 1386, Grand Duke of Lithuania Jogaila was crowned King of Poland, and allied the Grand Duchy with Kingdom of Poland in a personal union. The union was formed between Jogaila and the daughter of King Luis of Poland, Jadwiga, by marriage. This was seen by the Polish as a move to end a union with Hungary. In the early parts of the This personal union eventually resulted in the Polish-Lithuanian Commonwealth, a federation created in 1569. The Muscovites, led by Tsar Ivan the III, began military conquests in 1486 to try and gain the Kievan Rus’ lands, specifically Belarus and Ukraine. The union between Poland and Lithuania ended in 1795, with the commonwealth partitioned and annexed by Imperial Russia, Prussia, and Austria. Belarusian territories remained part of the Russian Empire until they were occupied by Germany during World War I.

Belarus first declared independence on 25 March 1918, forming the Belarusian People’s Republic. The Republic, however, was short-lived, and the regime was overthrown soon after the German withdrawal. In 1919, Belarus became the Byelorussian Soviet Socialist Republic (BSSR). After Russian occupation of eastern and northern Lithuania, it was merged into the Lithuanian-Byelorussian Soviet Socialist Republic. After the Polish-Soviet War ended in 1921, Byelorussian lands were split between Poland and the Bolsheviks, and the recreated Byelorussian SSR became a founding member of the Union of Soviet Socialist Republics in 1922.

In September 1939, as a result of the Molotov-Ribbentrop Pact, the Soviet Union invaded Poland and annexed its eastern lands, including majority of Polish-held Byelorussian land. In 1941, Nazi Germany invaded the Soviet Union. Byelorussia was occupied soon after and remained in Nazi hands until 1944. Over one million buildings were destroyed and the human losses totaled over two million Belarusians. The Jewish population of Belorussia was devastated during The Holocaust. The population of Belarus did not regain its pre-war level until 1971. The Jewish population, however, never recovered.

After the war ended, Byelorussia was among the fifty-one signatories to the founding of the United Nations Charter in 1945. After the war, Belarus began a process of rebuilding, with help from Moscow. During this time, Belarus became a major center of manufacturing in the western region of the USSR. The increase in jobs brought in a huge immigrant population from the Russian Soviet Federated Socialist Republic.

Under the control of Joseph Stalin, a policy of Sovietization was started to “protect” Byelorussian SSR from influences by the West. This policy involved sending Russians from various parts of the Soviet Union and placing them in key positions in the Belorussian SSR government. The official use of the Belarusian language and other cultural aspects were limited by Moscow. After Stalin died in 1953, his successor, Nikita Khrushchev, continued this program, stating, “The sooner we all start speaking Russian, the faster we shall build communism.”[16] When Soviet premier Mikhail Gorbachev began pushing through his Perestroika plan, the Belarusian people delivered a petition to him in December 1986 explaining the loss of their culture. This event has been coined by historians as the “cultural Chernobyl”. (Earlier that year, Belarus was exposed to nuclear fallout from the explosion at the Chernobyl power plant in neighboring Ukrainian SSR.)[18] In June of 1988, mass graves were discovered at the city of Kurapaty. The graves allegedly contained about 250,000 of Stalin’s victims.[18] Some contend that this discovery was proof that the Soviet government was trying to erase the Belarusian people, and caused some to seek independence.

After the discovery of the mass graves by archaeologist Zyanon Paznyak, it caused some Belarusians to press Moscow on why this happened. After clashes with the police, the Belarusian Popular Front was created in October of 1988, having Paznyak as the chairman of the new party. Two years later in March of 1990, elections for seats in the Supreme Soviet of the BSSR took place. While only 10% of the seats were taken by the BPF, the populace was content with the selection of the delegates. Belarus declared itself sovereign on 27 July 1990, by the issuance of the Declaration of State Sovereignty of the Belarusian Soviet Socialist Republic. The BSSR became the Republic of Belarus on 25 August 1991, days after the coup on Gorbachev, even with the support of the Communist Party of Belarus. Days after the declaration, Belarusian Prime Minister Vyachaslaw Kyebich and his entire cabinent renounced their membership in the CPB, soon stopping the activities of the CPB completely.

Around that time, Stanislav Shushkevich became Chairman of the Supreme Soviet of Belarus, the top leadership position in Belarus, after liberals replaced Mikalay Dzyemyantsyey for siding with the coup. The white, red, white flag and the Pahonia shield were chosen as the national symbols of Belarus. Shushkevich, along with Boris Yeltsin of Russia and Leonid Kravchuk of Ukraine, met on 8 December 1991, in Belavezhskaya Pushcha to formally declare the dissolution of the Soviet Union and the formation of the Commonwealth of Independent States, being headquartered in Minsk. In 1993, there was an agreement in the Supreme Soviet to reduce its service by one year, so that new elections could take place in 1994.

Before the 1994 elections, two events occurred that shaped Belarus forever. First, Shushkevich was ousted by a vote of no-confidence and replaced by a Kyebich ally, Myechyslaw Hryb. In March of that year, a national constitution was adopted, which replaced the office of prime minister with that of a president. With the first round of elections for president, the two candidates for the office were Kyebich and Alexander Lukashenko, who campaigned on a plan to rid the government of corruption. In the second round in July, Lukashenko was declared the winner with over 80% of the vote.[20] Since that election, Lukashenko has held the office of president, being reelected in 2001 and in 2006.

There appears to be a movement in Belarus towards reuniting with Russia. In November 2005, a draft constitution was sent to both Vladimir Putin and Lukashenko for approval. This move, along with others, is part of the 1996 plan created by Lukashenko and former Russian President Boris Yeltsin to create a union between the two nations.