The earliest sign of human habitation is a 62-foot-high (19m) prehistoric tumulus in the grounds of Marlborough College. Recent radiocarbon dating has found it to date from about 2400 BC. It is of similar age to the larger Silbury Hill about 5 miles (8.0km) west of the town. Legend has it that the Mound is the burial site of Merlin and that the name of the town comes from Merlin’s Barrow. More plausibly, the town’s name possibly derives from the medieval term for chalky ground “marl”—thus, “town on chalk”. However more recent research, from geographer John Everett-Heath, identifies the original Anglo-Saxon place name as Merleberge, with a derivation from either the personal name of Mærle combined with beorg (hill), or meargealla beorg: hill where gentian grows. On John Speed’s map of Wiltshire (1611), the town’s name is recorded as Marlinges boroe. The town’s motto is Ubi nunc sapientis ossa Merlini (“Where now are the bones of wise Merlin”).
Further evidence of human occupation comes from the discovery in St Margaret’s Mead of the Marlborough Bucket, an Iron Age burial bucket made of fir wood with three iron hoops, a top bar and two handles; it also sports bronze bands decorated with human heads and mythical animals, and is now on display at the Wiltshire Museum in Devizes.