John of Gaunt in Shakespeare's Richard II speaks of

These powerful lines may be seen as representing the unspoken assumption of so many historians that ‘England’ is for all intents and purposes an island. It is, of course, merely part, though now the most populated part, of the larger island of an Atlantic archipelago situated off the coast of north-west Europe. Shakespeare's poetry, however, may be taken as reflecting the almost total dominance which English culture, more properly perhaps the culture of south-eastern England, has achieved throughout the British Isles in the modern period. The typical inhabitant of the British Isles is today English-speaking (though a minority may speak Gaelic, or Urdu, at home).

The dominance of English culture marks the culmination of a complex and prolonged process, which is far from complete even today. As a historical starting point, however, it must be set on one side. For the purpose of ‘making sense’ of the history of the British Isles, we must go beyond the Anglo-Saxons and the Romans to the Celtic Iron Age, which left a lasting stamp upon the languages, place-names and cultures of these islands.

A full prehistory would need to go much further back, possibly to the mesolithic period of c. 7000 bc when human beings returned to the British Isles in the wake of a retreating Ice Age before land bridges between the islands and between Britain and the continent were finally washed away.