The Herrengrabenfleet is a fleet in downtown Hamburg.
From 1475 to 1547, a new fortification line with ramparts and ditches was built in front of the city moats of the 13th and 14th centuries to protect the urban area at that time (corresponding to today's Hamburg-Altstadt district). In 1499, the “Herrengraben” was built as an outer defensive ditch (city moat) in front of the late Middle Ages city wall, the Neuer Wall. On the inside, the Neuer Wall was lined with today's Alsterfleet. The name Herrengraben is said to go back to the exclusive fishing rights of the councilors (Senate members).
In 1546 the Herrengraben was widened and extended northeast through the Bleichenfleet, which reached almost to the Inner Alster. The defense line was moved west in 1625 and replaced by the Hamburg ramparts. In 1765 the Fleet was expanded into a 25 meter wide canal, deepened and connected to the Elbe.
The area between Herrengraben, Bleichenfleet and Alsterfleet is now called “Fleetinsel”, although it is not actually an island. The old buildings in this area are one of the last undestroyed ensembles of office buildings typical of Hamburg. The storage buildings from the 17th to 19th centuries could be supplied directly from the water; the office offices were located in the representative parts of the building facing Admiralitätstrasse. Since the late 1980s, Fleetinsel has been a center of the Hamburg art market: in addition to ten galleries for contemporary art, there are also art bookstores and studios.