The Vikings, the Danes and the Norsemen, arrived in the eighth and ninth centuries. Scandinavian elements in place-names and Scandinavian physique in the population are still distinct in eastern districts devastated by them and re-settled, and on the then frontiers of settlement in areas isolated by fen or marsh, in upland valleys and on western coasts. If Scandinavian colonists were few in relation to men of other stocks already established, the Norman-French settlers who came with King William were fewer still, and in physical type were closely related to groups long established.
Position close to Europe fostered from early times strong trading links with the Continent. Until the fourteenth century Britain's economy was that of a young society: a valuable raw material, wool, was traded for the luxury manufactures of the Low Countries, Italy and Byzantium, and for the fruits, the wines and spices, and the furs, the wax and the timber that Mediterranean and Hanseatic merchants brought. Britain lay on the narrow strait where sea-routes from the Mediterranean and from the Baltic met, and were joined across the water by the land-routes from the valleys of the Rhône and the Seine, the Alpine passes, the Danube and the Rhine, and the north European plains. By the end of the fourteenth century Britain's economy had changed: cloth of high quality to be finished abroad, and cheaper kinds dyed and finished at home, had replaced raw wool as a staple export. At the beginning of modern times British merchants were seeking even wider markets, and it was in part the need for new markets for their cloth that attracted British interest and capital to compete for a share in the new lands and ocean-routes explored by Spain and Portugal.
Position on the Atlantic shore gave freedom of movement on ocean-routes throughout the world, and from the late sixteenth century onwards, without losing the advantages of position where European sea-routes and land-routes met, the advantages of the new situation were pursued. Overseas trade grew, a great overseas empire was built, by the middle of the eighteenth century Britain lay at the nexus of the ocean routes, mistress of the seas. The commercial and financial capital of the world had shifted north-westward across Europe: from Byzantium to the Italian cities in medieval times, to Antwerp then to Amsterdam in the early modern world, to London in the eighteenth century.
The new position encouraged both immigration and emigration. Into Britain came the Flemings, the Dutch and the Huguenots in the sixteenth and seventeenth centuries, Jewish groups in many periods, Italians, Germans, Russians and Poles in the nineteenth and early twentieth centuries to share an expanding economy. They were, however, as were the Normany-Frenchmen before them, too few in numbers to affect significantly the British stock, although locally some for long formed groups culturally distinct. From Britain went forth explorers and many more settlers. From the seventeenth century when it is guessed that some 80,000 left Britain to settle the western seaboard of the Atlantic, a great stream of emigrants has moved overseas to find new homes: in the eighteenth century in the United States and Canada, in the nineteenth and twentieth centuries in South Africa and tropical Africa, in Australia and New Zealand too. This movement of population is of great importance to the geography of the island in that it affects the number and distribution of people at home, and, through the links they make, fosters trade abroad. Expanding trade allowed not merely the maintenance of increasing numbers in Britain, but also an increasingly higher standard of living.
During this period the volume and value of overseas trade steadily and rapidly increased though the items most important in it changed. It was not until the second half of the nineteenth century that food became a major item: in 1840 Britain still produced about 90% of the wheat consumed. From 1850 onwards increasing quantities of wheat were imported, until in 1939 Britain produced only 13 % of the wheat needed at home. The export trade at the beginning of the eighteenth century was dominated still by the export of woollen cloth which provided about half the total value of it; by 1800 though the export of woollen cloth had increased greatly it was outstripped by the export of cotton textiles: until 1850 cotton provided more than 40% of the export total. In 1850 Britain was already producing half the world's pig iron, and in the last half of the nineteenth century Britain dominated the world market in iron and steel, as railways largely built of British metal were flung across Europe and America, and machines, tools and implements of British iron and steel were demanded throughout the world. Coal was mined in increasing quantities: production rose from 4.7 m. tons in 1750 to 56 m. tons in 1850 to 287 m. tons in 1913, and coal exports rose from 3.8 m. tons in 1850 to 94 m. tons in 1913. The decades 1870-90 were those in which Britain's world position was most powerful, the value of its foreign commerce was greater than that of any other country; by the turn of the century the industries of Germany and the United States were beginning to compete, but not until the First World War was British supremacy seriously threatened. In 1921 the foreign commerce of the United States surpassed that of Britain. In the nineteen-twenties and thirties the world demand for British iron and steel decreased, the export value of textiles fell seriously as India and Japan not only satisfied their own demand but also became competitors in other eastern and in African markets. Coal exports declined too as mines in newer countries came into production, and the advantages of oil over coal became more and more obvious.