They were far from being compelled to this extraordinary migration by any want of subsistence at home; for it appears that they raised, without difficulty, as much corn in one year as supported them for two; they could not complain of the barrenness of such a soil.
This spirit of migration, which grew out of the ancient manners and necessities, and sometimes operated like a blind instinct, such as actuates birds of passage, is very sufficient to account for the early habitation of the remotest parts of the earth, and in some sort also justifies that claim which has been so fondly made by almost all nations to great antiquity.
Gaul, from whence Britain was originally peopled, consisted of three nations: the Belgae, towards the north; the Celtae, in the middle countries; and the Aquitani, to the south.

Britain appears to have received its people only from the two former.

From the Celtae were derived the most ancient tribes of the Britons, of which the most considerable were called Brigantes.

The Belgae, who did not even settle in Gaul until after Britain had been peopled by colonies from the former, forcibly drove the Brigantes into the inland countries, and possessed the greatest part of the coast, especially to the south and west.

These latter, as they entered the island in a more improved age, brought with them the knowledge and practice of agriculture, which, however, only prevailed in their own countries.