 Up until about the time of his death , Diarmait had been the most powerful king in southern Ireland . In consequence of the void left by his demise , Diarmait 's erstwhile ally Toirdelbach seized the initiative , and moved to enforce his own claim to the high @-@ kingship of Ireland . He immediately imposed his overlordship on Leinster — a task almost certainly expedited by the aforesaid infighting amongst the Uí Chennselaig — and took control of Dublin . Whilst the imposition of authority upon rival provincial kingdoms was a fundamental part in gaining the high @-@ kingship , Toirdelbach 's decision to march @-@ on Dublin reveals that the acquisition of this coastal kingdom had also become an essential part of the process . 
 Up until about the time of his death , Diarmait had been the most powerful king in southern Ireland . In consequence of the void left by his demise , Diarmait <a href='null_genetive' title='1'><mark>'s</mark></a>erstwhile ally Toirdelbach seized the initiative , and moved to enforce his own claim to the high @-@ kingship of Ireland . He immediately imposed his overlordship on Leinster — a task almost certainly expedited by the aforesaid infighting amongst the Uí Chennselaig — and took control of Dublin . Whilst the imposition of authority upon rival provincial kingdoms was a fundamental part in gaining the high @-@ kingship , Toirdelbach <a href='null_genetive' title='2'><mark>'s</mark></a>decision to march @-@ on Dublin <a href='uninflect' title='3'><mark>reveals</mark></a> that the acquisition of this coastal kingdom <a href='been_done' title='4'><mark>had</mark></a> also become an essential part of the process . 
Up until about da time of his death , Diarmait had been the most powerful king in southern Ireland . In consequence of the void left by his demise , Diarmait  erstwhile ally Toirdelbach seized the initiative , and moved to enforce his own claim to tdahigh @-@ kingship of Ireland . He immediately imposed his overlordship on Leinster — a task almost certainly expedited by thdaforesaid infighting amongst the Uí Chennselaig — and took control of Dublin . Whilst thedaposition of authority upon rival provincial kingdoms was a fundamental part in gaining the high @-@ kingship , Toirdelbach  decision to march @-@ on Dublin reveal that the acquisition of this coastal kingdom done also become an essential part of the process .