Now all those conditions have controlled the history of Britain, sometimes together, sometimes separately.
Set at the end of the world, Britain was for long ages the last refuge of many tribes who entered at the continental angle at Dover, and were forced by later immigrants farther and farther towards the north-west. What the force was that impelled those people to cross to Britain, whose shores they could see from the con tinent, we cannot say, though we may surmise. Each successive wave of immigrants seems to have had a higher form of civilization than the preceding ; they were more able to use energy in either war or peace. The methods of using and saving energy they had learned, no doubt, from other people, but as they were only imitators they scarcely counted in history. Then at last the English lowland became part of the Roman Empire; and Britain was brought into the world.
With the departure of the Romans, the fact that Britain wa§ an island continued to have effect. was then no central organization within Britain, so that the fact that Britain was an island resulted in successful attacks on all sides by seamen who came from over the North Sea. The Saxons and Jutes and Angles and Danes and Norsemen attacked on south and east and north and west, setting up small states and introducing customs and ways of living the influence of which is felt to this day. There was even for a few years an empire based on the North Sea and including practically all the lowland of England.
At length the Channel was again crossed by the Nor mans, and the lowland of England was strongly ruled from within by William and his sons. The rule natur ally centred in London. Near the head of the tideway, and on the first firm ground amid the marshes of the northern bank, it was marked out as the crossing place to which roads converged in the Lower Thames Valley, as well as the point to which ships might come. Between the Downs and the Chilterns it had no rival; only in the other basin entered by Southampton Water, had there been another possible centre at Winchester. It appeared for a time as if the plains of Northern and Western France might also be ruled from the English centre : the Angevin kingdom stretched from the Cheviots to the Pyrenees. Then the fact that Britain is
an island began to control history in other ways : the natural jealousies of peoples speaking alien tongues asserted themselves, and the peoples of what is now France, hating the ruler in Paris who spoke French rather less than the ruler across the Channel in London who spoke English, eventually united round Paris to form the French nation. Yet the Channel Islands never belonged to France : they were held by the Nor mans before they conquered England, and- remain as a reminder that for many centuries in British history the sea was not a protection, but a means of approach for seamen.
Then the centralized government in the English lowland gradually came to control more than the low land. For long the highland of Wales, with different characteristics, was a land apart; for long the lowland of Scotland, with a central government of its own, had an independent existence defended as it was by the broad stretch of moorland, inhabited only by raid ing cattle thieves, which fills all the north of England and the south of Scotland. Neither in Roman times nor for more than a thousand years thereafter was Great Britain one : the highlands here, as always, tended to produce different political conditions as a result of different economic conditions. But eventually the whole island became one centralized political unit, defended by the sea and using the sea as a defence.
Within this political unit, and while the lowlands were still separate, energy was being accumulated. Wool was obtained from sheep fed on grass, which could grow all the year round; sheep could be kept, because the strong government guaranteed alike freedom from invasion, and an absence of anarchy. The wool was sold to merchants overseas. Gradually a trade grew up by which further energy was accumulated, due to the fact that men could work all the year round, and ships could come far inland with and for their cargoes. This advance was possible, not only because a protection was afforded all round by the sea, but also because there was a central government. England became, in fact, the first centralized European state of modern times.