Germany’s partition occurred through Allied negotiation at the end of World War II. The East came under Soviet control, with further partition of the city of Berlin into Western and Eastern Zones of occupation. From 1985, Mikhail Gorbachev introduced liberalizing policies of glasnost (openness) and perestroika (restructuring) designed to avert economic collapse in the Soviet bloc. Instead, they spurred a wave of revolutions: when the wave reached Hungary, it opened its borders, inspiring thousands of East Germans to cross Hungary en route to the West. Events then moved with breakneck speed; in November 1989, the Berlin Wall was opened, then demolished, and free elections hastily arranged in East Germany were overwhelmingly won by a pro-Unification coalition. On 18 May 1990, the two Germanies signed a treaty agreeing monetary, economic and social union. Formal political union was effected on 3 October, adding six new Länder to the Federal Republic of Germany.
— OR —