Germany became one nation when the kingdom of Prussia united with various German states in 1871. Its first stamp was issued in 1872. “Germania” definitives were issued 1900-22 – the longest-running German stamp series. They were also used where Germany had foreign post offices, and in countries Germany occupied in World War I. (Many states, such as Bavaria, issued their own stamps.) After World War II, Germany was divided into zones by the U.S., France, Great Britain, and U.S.S.R. In 1948, German stamps of 1947-48 were overprinted for use in the Soviet zone, becoming East Germany (German Democratic Republic). “DDR” was inscribed on its stamps until reunification with West Germany (German Federal Republic) in 1990.