Hamburgs official name is "Free and Hanseatic City of Hamburg" showing the connection between the city and the Hanseatic League as well the its free city status as part of the Holy Roman Empire.
Hamburg was founded in 808AD when Emperor Charlemagne ordered a castle to be built on the rocky ground between Alster and Elbe as a defence against the Slavs. The castle was named Hammaburg (Hamma Castle). It is not clear where the Hamma comes from.
Hamburg was designated the seal of a Roman Catholic Bishopric in 834 and was united with Bremen in 836.
Hamburg has been heavily damaged several times:
- 845; It was invaded and destroyed by Vikings who sailed up the river Elbe in 600 ships. It had an approximate population of 500.
- 1030; King Mieszko II Lambert of Poland burned down the city.
- 1201 and 1214; Valdemar II of Denmark raided and occupied Hamburg.
- Hamburg experienced several great fires, most notably in 1284 and 1842.
- 23/07/1943; a firestorm developed as a result of Allied firebombing