Civil wars in Western Europe had rendered the nations there incapable of effective resistance to the ruthless invaders. The Vikings descended now at one point, now at another. When they met with a more stubborn resistance than usual, they merely retired to their ships with whatever plunder they had seized, and sailed away to make an attack somewhere else. They wintered on the islands which they had seized, and as soon as spring was come they descended once more on the devoted lands. Ireland suffered severely at their hands. The Orkneys and the Hebrides became nests of Vikings; in fact, colonies of them must have been established there at a very early date. In these islands they were safe from all interference—a law to themselves; for as yet there was no arm in Europe long enough and strong enough to reach them. Nowhere could a more convenient base have been found for Viking raids on the British and Irish shores. The first half-century of the Viking Age saw the Danes settled merely in outlying parts of the east coast of England. The Norsemen, on the other hand, had already seized on Orkney, Shetland, the Hebrides, and large tracts of Eastern Ireland. The first fifty years of the Viking Age may be called the first period of Norse colonization in the west. It would be a great mistake, however, to suppose that the Norsemen were merely turbulent sea-robbers, or that the only result of their migrations was to hinder the progress of civilization in Western Europe. As settlers in other countries, they brought new strength and vitality to the land of their adoption; but instead of remaining separate colonies, they were soon absorbed into the native population, and had no further history of their own. Yet there were two great settlements abroad which left a deep mark on European history. The one was the colonization of the north of France, afterwards called Normandy. There the Norsemen soon adopted the language and the religion of the country, but retained so much of their native characteristics that the subsequent Norman Conquest of England may be regarded as really a Norse inroad of a specially successful type. The other settlement was that in the south of Italy and Sicily, later known as the kingdom of the Two Sicilies, which occupied an important place in history during the Middle Ages. Even the British settlements for the most part had only a brief period of separate history, and soon became merged into the general stream of national life. In Orkney and Shetland, however, where there was probably no native population at the time of the Norse invasion, the colony developed along its own special lines, and has left behind it a history which for centuries remained distinct from that of the rest of Great Britain.