 In 1166 , Mac <unk> had fled to <unk> , France , following a war involving <unk> Ua <unk> , of <unk> , and sought the assistance of the <unk> king , Henry II , in <unk> his kingdom . In <unk> , 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 <unk> and the <unk> @-@ Norman <unk> and persuaded many of the Irish kings to accept him as their overlord , an arrangement confirmed in the 1175 Treaty of Windsor . 
