Why was Poland the first to break away from the Soviet Bloc?

Answer 1

Poland was always one of the most loosly controlled countries in the Soviet Bloc. While the government of Poland was communist and the government was strongly influenced by the Soviet Union, Poland was relatively independent.

In the 1960s, the communist government in Poland was forced to dramatically raise food prices in order to prevent economic collapse. This decision led to strikes and protests. To remedy the situation, the government resorted to large scale borrowing from the west, but this decision ultimately had a lot to do with the downfall of the communist government.

The 1978 election of Karol Wojtyla as Pope John Paul II and the opposition of the Roman Catholic Church to the communist government helped solidify the position of those who opposed the govenment. In 1980, trade unions including 'Solidarity' formed by Lech Walesa organized labor strikes to protest the living conditions which had, once again, become very harsh.

Finally, faced with massive foreign debt, the communist government of Poland was forced to negotiate with opponents from the trade unions and the Roman Catholic Church. Free Parliamentary elections were held and the communists were defeated.

Answer 2

You have some good answers already, but the word "successfully" should appear in your question. Czechoslovakia and Hungary had tried much earlier but had been crushed.
And Albania and Yugoslavia were always odd birds, never quite completely under Soviet control.

Answer 3

Lech Walessa and his union "Solidarity" and pope John Paul II