Godred's rise in the Irish Sea region appears to have provoked William II to protect the north-western reaches of his realm, the participation of the Islesmen in war-wracked northern Wales may have provoked a similar response. The activity of the Islesmen in the region, and the prospect of their consolidation on Anglesey, may well have posed a potential threat to English interests in the area. Certainly, Historia Gruffud vab Kenan records that William II launched an utterly unsuccessfully campaign into the region, directed at Gruffudd himself, and that the English were forced to turn back without having gained any plunder. Nevertheless, an alternate possibility is that William II had been lured into the region by the native resurgence throughout the Welsh Marches—an event in which Gruffudd's participation is uncertain. Whatever the reason, the English counter-operation appears to have been undertaken with mainly defensive objectives in mind. Downfall and death Godred's rule in Dublin lasted until 1094. That year the Annals of Inisfallen reveal that warfare broke out between Muirchertach and a northern Irish alliance that included Godred. This source and the seventeenth-century Annals of Clonmacnoise, the Annals of the Four Masters, and the Annals of Ulster, reveal that Muirchertach marched upon Dublin where he was confronted by the alliance. Godred's maritime force in this campaign is numbered at ninety ships by the seventeenth-century Annals of the Four Masters. Although all these sources indicate that Muirchertach's forces were at first forced to flee, Muirchertach soon returned after the alliance had dispersed, and succeeded in driving Godred from Dublin. The Annals of Inisfallen appears to indicate that warfare between Muirchertach and Godred was wrought throughout the year. The source also reveals that, during Dublin's fall, Muirchertach captured Conchobar Ua Conchobair Failge, King of Uí Failge. Although the Kingdom of Uí Failge had previously enjoyed the patronage of the Uí Briain, it is possible that Godred had forged an alliance with Conchobar. Following the Uí Briain conquest of Dublin, the Ua Conchobair kings of Uí Failge may have been the only Leinster lords who refused to acknowledge Muirchertach's overlordship. From a late-eleventh-century Irish perspective, dominance of Dublin appears to have been a virtual prerequisite of gaining the Irish high-kingship, and Muirchertach's quest for control of this coastal kingdom appears to have been undertaken in such a context. In fact, it is evidence that Godred had allied himself with Muirchertach's fiercest rival for the