 In 1166 , Mac Murrough had fled to Anjou , France , following a war involving Tighearnán Ua Ruairc , of Breifne , and sought the assistance of the Angevin king , Henry II , in recapturing his kingdom . In 1171 , Henry arrived in Ireland in order to review the general progress of the expedition . He wanted to re @-@ exert royal authority over the invasion which was expanding beyond his control . Henry successfully re @-@ imposed his authority over Strongbow and the Cambro @-@ Norman warlords and persuaded many of the Irish kings to accept him as their overlord , an arrangement confirmed in the 1175 Treaty of Windsor . 
