From the Viking word-hoard

At the beginning of the ninth century the growing population of the three great branches of the Scandinavian race who peopled the countries abutting the Baltic - the Norsemen or Northmen, the Swedes and the Danes - began a great outward movement, caused both by political changes and their enterprising nature. Thus the ninth century came to be known as the Age of the Vikings, Vikinga-Old.

The Danish emigration directed its course to the north-cast of England. The second migration was Norse, whose settlers gradually peopled the coasts of Ireland, northern Scotland and the Isle of Man. They left a lasting linguistic heritage. This book is a glossary of words in the various languages of Britain and Ireland which owe their origin to the intrepid raiders and merchants of Scandinavia. --Book Jacket.