It is but natural that the ancient Norwegians should become warlike and brave men, since their firm religious belief was that those who died of sickness or old age would sink down into the dark abode of Hel (Helheim), and that only the brave men who fell in battle would be invited to the feasts in Odin's Hall. Sometimes the earls or kings would make war on their neighbors, either for conquest or for revenge. But a time came when the countries of the north with their poorly developed resources became overpopulated, and the warriors had to seek better fields abroad. The viking cruises commenced, and for a long time the Norwegians continued to harry the coasts of Europe. At first the viking expeditions were nothing but piracy, carried on for a livelihood. The name Viking is supposed to be derived from the word _vik_, a cove or inlet on the coast, in which they would harbor with their ships and lie in wait for merchants sailing by. Soon these expeditions assumed a wider range and a wilder character, and historians of the time paint the horrors spread by the vikings in dark colors. In the English churches they had a day of prayer each week to invoke the aid of heaven against the harrying Northmen. In France the following formula was inserted in the church prayer: "_A furore Norman norum libera nos, o Domine!_" (Free us, O Lord, from the fury of the Northmen!) Gradually the viking life assumed a nobler form. There appear to be three stages or periods in the viking age. In the first one the vikings make casual visits with single ships to the shores of England, Ireland, France or Flanders, and when they have plundered a town or a convent they return to their ships and sail away. In the second period their cruises assume a more regular character, and indicate some definite plan, as they take possession of certain points, where they winter, and from where they command the surrounding country. During the third period they no longer confine themselves to seeking booty, but act as real conquerors, take possession of the conquered territory and rule it.