Hamburg flag 10 x 15 cm
Stab ca. 30 cm, Fuß Durchmesse 6 cm, Fuß Höhe 4,5 cm, Material Fahne Polyester, Stab und Fuß Kunststoff schwarz

Hamburg is the second-largest city in Germany (after Berlin), and is the most populous non-capital city in the European Union. The city is home to approximately 1.8 million people, while the Hamburg metropolitan area (including parts of the neighboring Federal States of Lower Saxony and Schleswig-Holstein) has more than 4.3 million inhabitants. The port of Hamburg is the second-largest port in Europe (after that of Rotterdam), and the ninth-largest in the world.

There are three flags of Hamburg, Germany. The Landesflagge (civil flag), the State flag of Hamburg (Staatsflagge) and the admiralty flag (Admiralitätsflagge) consist of the Coat of arms of Hamburg on a red flag.

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-1500s, 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.

The civil flag is free for use to everybody. The state flag of Hamburg is only used by the Senate of Hamburg as the head of state. This flag was created in 1897 on the occasion of the opening of the new town hall. The Admiralty flag of Hamburg is used only for state buildings connected to the navigation, since there are no warships as of 2008. It is including the admiralty coat of arms which are existing since 1642..

reference: http://en.wikipedia.org/wiki/Flag_of_Hamburg