The history of attempts to explain the name of London is charted, and it is concluded that none of them succeeds in making any headway with the problem. A tentative new solution is proposed which explains it as a probably Celtic place-name derived from a Celticized river-name originally forming part of the Old European stratum of European toponymy, in the sense established by Hans Krahe. Topographical arguments are used to support the proposal, as well as arguments from pre-English naming patterns for rivers and their estuaries. The proposed etymology also succeeds in accounting for the Middle Welsh name of the city,Llundein, without any of the special pleading associated with current explanations.