Flag of Germany
With the formation of the short-lived Weimar Republic after World War I, the tricolour was adopted as the national flag of Germany. Sixteen years later following World War II, the tricolour was again designated as the flag of both West and East Germany divided states in 1949. The two flags were identical until 1959, when the East German flag was augmented with the coat of arms of East Germany. Since reunification on 3 October 1990, the black-red-gold tricolour has become the flag of a reunified Federal Republic of Germany.
Flag of Hamburg
The civil flag shows a white castle with three towers on red background, which is used as a civil flag as a state flag for most purposes. (It was historically used as civil ensign as well.) The oldest seal with the castle is thought to date from 1241. The first flag featuring the current form was in the mid-16th century, although this was most probably a red field, a white escutcheon and red castle. After about 1623, the escutcheon began to be omitted, leaving a red castle on white or a white castle on red. It was only in 1751 that the white castle on red was decreed as the flag of Hamburg.