Germany began to use the Euro as its sole currency on Jan. 1, 2002, officially replacing the Deutsche Mark. The German government had previously adopted the Euro as its acceptable currency during a transitional time that started in January 1999. During this three-year transitional period, the Mark remained legal tender.
The collapse of the German economy and any semblance of a currency during World War II necessitated the creation of a new currency during the foreign occupation of Germany following the war. The authorities in the American-occupied zone adopted the Deutsche Mark, while those in the Soviet-occupied zone used the ostmark. The Deutsche Mark served as the official currency of West Germany beginning in 1948 until the unification of Germany in 1990, at which point it became the national currency.