have resulted in the submission or expulsion of Echmarcach altogether, effectively giving Diarmait control over the Irish Sea region. When Murchad died in 1070, Diarmait assumed control of Dublin and perhaps Mann as well. The ruler of Mann in about 1066 was Gofraid mac Sitriuc, King of the Isles, a man who appears to have reigned under Diarmait's overlordship. Like Godred himself, Gofraid mac Sitriuc may have been a descendant of Amlaíb Cúarán. On Diarmait's unexpected death in 1072, Toirdelbach Ua Briain, King of Munster invaded Leinster, and acquired control of Dublin. Within a year of gaining lordship over the Dubliners, Toirdelbach appears to have installed, or at least recognised a certain Gofraid mac Amlaíb meic Ragnaill as their king. In fact, this man appears to have been a close kinsman of Echmarcach, possibly his nephew. As such, Gofraid mac Amlaíb meic Ragnaill seems to have been a member of a Norse-Gaelic kindred possessing close marital links with the Uí Briain. Such links may well explain the remarkable rapidity with which the Uí Briain struck out at Dublin and the Isles after Diarmait's demise. In 1073, for instance, Mann was raided by a certain Sitriuc mac Amlaíb and two grandsons of the Uí Briain founder, Brian Bóruma, High King of Ireland. Whilst there is reason to suspect that Sitriuc was a brother of Gofraid mac Amlaíb meic Ragnaill, the attack itself was almost certainly a continuation of the Uí Briain's conquest of Dublin the year before. Emergence in the Isles Godred seems to have spent his early career as a mercenary of sorts. Certainly the Chronicle of Mann states that he took part in the ill-fated Norwegian invasion of England in 1066. This Norwegian campaign culminated in the Battle of Stamford Bridge, a bloody autumn encounter in which Harold Godwinson, King of England utterly destroyed the forces of Haraldr Sigurðarson, King of Norway in north-eastern England. The slaughter at Stamford resulted in the total destruction of Norwegian military power, and it took almost a generation before a king of this realm could reassert authority in the Norse colonies of the British Isles. If the eleventh-century chronicler Adam of Bremen is to be believed, an Irish king was slain during the battle, which could indicate that Godred formed part of the Irish Sea contingent, a host perhaps led by the slain king. At any rate, it was in the aftermath of