West Germany is the common English name for the Federal Republic of Germany between its formation on 23 May 1949 and German reunification through the accession of East Germany on 3 October 1990. During this Cold War period, the western portion of Germany and West Berlin were parts of the Western Bloc. West Germany was formed as a political entity during the Allied occupation of Germany after World War II, established from eleven states formed in the three Allied zones of occupation held by the United States, the United Kingdom, and France. Its provisional capital was the city of Bonn, and West Germany is retrospectively designated as the Bonn Republic.
At the onset of the Cold War, Europe was divided between the Western and Eastern blocs. Germany was de facto divided into two countries and two special territories, the Saarland and a divided Berlin. Initially, West Germany claimed an exclusive mandate for all of Germany, identifying as the sole democratically reorganised continuation of the 1871–1945 German Reich.
Three southwestern states of West Germany merged to form Baden-Württemberg in 1952, and the Saarland joined West Germany in 1957. In addition to the resulting ten states, West Berlin was considered an unofficial de facto eleventh state. While legally not part of West Germany, as Berlin was under the control of the Allied Control Council, West Berlin politically aligned with West Germany and was directly or indirectly represented in its federal institutions.
The foundation for the influential position held by Germany today was laid during the economic miracle of the 1950s (Wirtschaftswunder), when West Germany rose from the enormous destruction wrought by World War II to become the world’s third-largest economy. The first chancellor Konrad Adenauer, who remained in office until 1963, worked for a full alignment with NATO rather than neutrality, and secured membership in the military alliance. Adenauer was also a proponent of agreements that developed into the present-day European Union. When the G6 was established in 1975, there was no serious debate as to whether West Germany would become a member.
Following the collapse of the Eastern Bloc, symbolised by the opening of the Berlin Wall, both territories took action to achieve German reunification. East Germany voted to dissolve and accede to the Federal Republic of Germany in 1990. Its five post-war states (Länder) were reconstituted, along with the reunited Berlin, which ended its special status and formed an additional Land. They formally joined the federal republic on 3 October 1990, raising the total number of states from ten to sixteen, and ending the division of Germany. The reunited Germany is the direct continuation of the state previously informally called West Germany and not a new state, as the process was essentially a voluntary act of accession: the Federal Republic of Germany was enlarged to include the additional six states of the former German Democratic Republic. The expanded federal republic retained West Germany’s political culture and continued its existing memberships in international organisations, as well as its Western foreign policy alignment and affiliation to Western alliances such as the United Nations, NATO, OECD, and the European Economic Community. (Wikipedia)