Berlin was formerly the capital of Prussia, an independent kingdom issuing stamps from 1850-67. It became Germany’s capital in 1871 with the unification of Prussia with various German states. After the second World War Berlin was divided into four sectors, one for each World War II Allied power: U.S., Britain, France, and Soviet Union. Each issued its own stamp series, including the “Berlin Bears” under Soviet occupation in 1945. In 1945-46, the Allied Military Government, consisting of the U.S. and Great Britain, issued the “A.M.G.” series. The French sector issued its own series, inscribed “Zone Française.” In 1948 the city was divided into East and West. West Berlin continued issuing stamps until re-unification in 1990.