FOSSIL hominids from the earlier Middle Pleistocene of Europe are very rare and the Mauer mandible is generally accepted as the most ancient, with an estimated age of 500 kyr(1,2). We report here on the discovery of a human tibia, in association with stone tools, from calcareous silts at the Lower Palaeolithic site of Boxgrove, West Sussex, UK3,4 (Fig. 1). The silt units are correlated by mammalian biostratigraphy to an, as yet unnamed, major temperate stage or interglacial that immediately pre-dates the Anglian cold stage(5). Accordingly, the temperate sediments are equated with oxygen isotope stage 13 (ref. 6) and are therefore roughly coeval with the Mauer mandible. The massive tibia is the oldest hominid fragment from the British Isles and provides the first information about the manufacturers of the early Acheulian industries of Europe. It is assigned to Home cf. heidelbergensis.