River Mole in 1613. In John Speed's 1611 map of Surrey this stretch of the river is denoted by a series of hills accompanied by the legend "The river runneth under". However the river's name is unlikely to have derived from this behaviour: The "Oxford Dictionary of English Place Names" suggests that "Mole" either comes from the Latin "mola" (a mill) or is a back-formation from "Molesey" (Mul's island). In John Rocque's 1768 map of Surrey, the name "Moulsey River" is used. In common with much of the rest of the Weald, the earliest evidence of human settlement along the Upper Mole
River Mole is thought to have merged with the River Wey near Byfleet and then flowed in a north-easterly direction via Richmond to meet the proto-Thames near Ware in Hertfordshire, (today the Mole and Wey are less than apart at their closest point near Painshill Park). During the Middle Pleistocene period, a large ice sheet built up across much of the East of England, reaching as far south as St Albans and Chelmsford, blocking the path of the proto-Thames. Glacial meltwater from the Anglian ice sheet, caused the Thames to divert southwards and flood the valley of the Mole–Wey river, thus adopting