On this day in 1968, Soviet Union-dominated Warsaw Pact troops invaded Czechoslovakia, crushing the Prague Spring.
On this day in 1991, more than 100,000 people rallied outside the Soviet Union's parliament building protesting the coup aiming to depose President Mikhail Gorbachev.
On this day in 1991, Estonia, annexed by the Soviet Union in 1940, issued a decision on the re-establishment of its independence.