Although Landsbergis was never a dissident, he strongly resented Soviet rule in Lithuania, established during World War II. In 1988, he was a founding member and then chairman of the Lithuanian reform movement, Sajūdis. The following year, Landsbergis was chosen as one of Lithuania's deputies to the Soviet Congress of People's Deputies, and in early 1990 he was elected to the Supreme Council (parliament) of Lithuania.
Initially, the Sajūdis movement claimed to support Soviet leader Mikhail Gorbachev's reformist perestroika policies, but it soon became clear that most Lithuanians would settle for nothing less than full independence. On 11 March 1990, the Lithuanian Supreme Council declared full and unconditional independence. Landsbergis was then elected president of the Supreme Council and in effect the head of state. Moscow responded by imposing an economic blockade on Lithuania, and on 13 January 1991 fourteen Lithuanians died during a Soviet crackdown on protesters in Vilnius.
Landsbergis had criticized Western leaders for supporting Gorbachev's policies while at the same time sidestepping Lithuania's rightful claim to independence. His ideological and uncompromising stand caused some irritation in the West, not to mention in Moscow, but in Lithuania it was supported and admired. After the abortive putsch against Gorbachev's regime in August 1991, Lithuania finally achieved unconditional independence.
Following his defeat in the 1992 parliamentary elections, Landsbergis became leader of the opposition. The following year, he was elected chairman of the Lithuanian Conservative Party. During 1996–2000, he was once again president of the Lithuanian parliament and head of state. Landsbergis withdrew from politics in 2002.
Lieven, Anatol. The Baltic Revolution: Estonia, Latvia, Lithuania and the Path to Independence. London and New York: Yale University Press, 1993.