ABSTRACT
The Norsemen's exploitation of the natural harbours of Ireland led to a rapid expansion of the trade which had long existed with France and Spain, and the opening up of commerce with the north European countries and the east. The expansion of trade in turn resulted in the ever-increasing growth in wealth and importance of trading centres and would thus automatically tend to cause the Norsemen to develop coastal rather than inland colonies. The appropriation of the coast by the Norsemen does not, however, imply that the area they settled in Ireland was insignificant and that they were isolated from the native population. The history of the Scandinavian occupation of Ireland is usually regarded as falling into two periods separated by the battle of Clontarf in 1014. The prevalence of intermarriage and interfosterage must have led to mutual understanding of each other's language, widely different as Old Norse and Irish were.
