The oldest proto-human bones uncovered in the area date from 700,000 years ago. The discovery, of Homo erectus remains, was made in what is today Norfolk and Suffolk.[22] At that time, Great Britain was joined to mainland Europe by a large land bridge, with a large river flowing westwards along the line of the later English Channel, fed by tributaries that would later become the Thames and the Seine. This area was greatly depopulated during the period of the last major ice age, as were other regions of the British Isles. In the subsequent recolonisation, after the thawing of the ice, genetic research suggests that present-day England was the last area of the British Isles to be repopulated, about 13,000 years ago.[23] The migrants arriving during this period contrast with the other of the inhabitants of the British Isles, coming across lands from the south east of Europe, whereas earlier arriving inhabitants came north along a coastal route from Iberia. These migrants would later adopt the Celtic culture that came to dominate much of western Europe, and spoke various related Brythonic languages.
By AD 43, the time of the main Roman conquest of Britain, Britain had already been the target of frequent invasions, planned and actual, by forces of the Roman Republic and Roman Empire. It was first invaded by Julius Caesar in 55 BC, but more successfully by the Emperor Claudius in 43 AD. Like other regions on the edge of the empire, Britain had long enjoyed trading links with the Romans, and their economic and cultural influence was a significant part of the British late pre-Roman Iron Age, especially in the south. With the fall of the Roman Empire 400 years later, the Romans left the Province of Britannia, much of which later came to be known as England.