The existence of Britain and Ireland posed a problem for the geographers of the Classical world ( Fig. 1.1 ). Their experience was limited to the Mediterranean where they had devised a scheme which saw the cosmos as a circular disc with the sea at its centre. For Hecataeus of Miletus, the land extended northwards into what is now Europe, southwards into Africa, and to the east as far as India, but beyond all these regions there was a river, Oceanus , which encircled the earth and marked the outer limit of the world ( Fig. 1.2 ). Only the dead could reach its farther shore; for Procopius writing in sixth-century Byzantium Britain was a land of ghosts (West 2007 : 390). There were two routes communicating directly between the inner sea and the most distant margin of the land. One was by the Arabian Gulf, whilst the second led through the Straits of Gibraltar into the Atlantic (Cunliff e 2001a : 2-6).Strictly speaking, the two islands studied in this book were beyond the limits of the world and so they could not exist, yet, as often happens, theory came into confl ict with practical experience. Long before the expansion of the Roman Empire there were reasons for questioning the traditional cosmology. Not long after 4000 bc axes made in the western Alps were distributed as far as the north of Scotland (Pétrequin et al. 2012 . It is no longer believed that Stonehenge was designed by a Mycenaean architect, but there seem to have been some connections between Britain, Northern Europe and the Aegean during the second millennium bc (Kristiansen and Larsson 2005 ). In the fi rst millennium, contacts between the Mediterranean and these outer islands intensifi ed during what is known as the Atlantic Bronze Age (Ruiz-Gálvez Priego 1998 ), and, later still, there are ceramic vessels of Greek origin among the fi nds from the Thames and other English rivers where they occur in similar contexts to metalwork of local manufacture and must have been deposited during the Iron Age (Bradley and A. Smith 2007 ).