Turning to historic times it would appear that from A.D. ioo to A.D. 8oo the country was ruled by a Gaelic aristocracy and it may be that this rule was over peoples of many distinct races. Prior to the Norse invasions of about 8oo A.D. there was a unity of civilisation, law and language under a Gaelic High Kingship. Ireland was not conquered by the Romans. The Norse invaders established colonies and fortresses round the coast and these were especially strong at Dublin, Wexford, Waterford, Cork and Limerick. For two hundred years they tried to subdue the country but their attempts ended when Brian Boru routed their Dublin garrison in i 014. With the centre of their power destroyed the Norsemen's coastal settlements became isolated communities enjoying citizen rights under the High Kingship. After a period of unsettled Gaelic rule, Ireland experienced a tide of Anglo-Norman invasion and settlement from i i66 to about 1300. This flow was mainly into south and east Louth, Meath, the eastern half of Westmeath,