From the Old English dun (hill) and Old Norse holmr (island or plateau). In 1000, it was recorded as Dunholm and, later, as Dunelm. It refers to the land enclosed by a loop of the River Wear which was a natural fortress. Holmr crops up in many places in English place names and language and meant, in its strictest sense anything raised and flat. On medieval ships, for example, the raised flat area at the rear was know as the helm (it did not then refer to the actual steering gear which was usually mounted there).