HUNGARY
1956: Spontaneous student demonstrations against communist policies erupted during a three-week period but were crushed by Soviet troops and tanks. 3,200 were killed.
1989: In May, government liberalization led to open borders, allowing East Germans fleeing to the West to pass through - creating the first tears in the Iron Curtain. Freedom House considers Hungary mostly free today.
Results: Mixed
CZECHOSLOVAKIA
1968: The "Prague Spring," - a period when Alexander Dubçek replaced communist hard-liners and began instituting democratic reforms called "socialism with a human face" - ended after nine months when tanks and troops from the armies of the Soviet Union, Bulgaria, Poland, and Hungary invaded.
1989: The three-week bloodless "Velvet Revolution" of peaceful protests ended with the resignation of communist President Gust√°v Hus√°k. Czechoslovakia was split into two separate nations in 1993. Today the Czech Republic and Slovakia are ranked among the most free nations in the world by Freedom House.
Results: Mixed
BULGARIA
1989: November demonstrations for political reform succeeded in winning Communist leader Todor Zhivkov's resignation. In June 1990, the first free elections were held, followed a year later by a new constitution. Despite continued economic crises and social unrest, the nation is rated as one of the world's most free by Freedom House.
Results: Successful
POLAND
1989: After a decade of political battles, the broad social movement created by the noncommunist trade union Solidarity triumphed in national elections in 1989, forming the first non-communist government in the Eastern bloc. Poland today is considered free by Freedom House.
Results: Successful
SERBIA
2000: Ten days of protests over a disputed presidential election ended with the convergence of protesters from all over the nation at Belgrade, forcing the resignation of President Slobodan Milosevic. The uprising set the precedent for the "color" revolutions to follow from Tbilisi to Kiev to Bishke. Freedom House ranks this nation as partly free.
Results: Mixed