[9] According to the twelfth-century Banshenchas, Domnall's father married Mór, daughter of Echmarcach mac Ragnaill, King of Dublin and the Isles.

[10] Toirdelbach Ua Briain died in 1086, and the Kingdom of Munster was partitioned between his three surviving sons: Muirchertach, Diarmait, and Tadc.

[18] According to the thirteenth- to fourteenth-century Chronicle of Mann, Gofraid was succeeded in the Isles by his eldest son, Lagmann,[19] who appears to have been forced to fend off factions supporting the claims of his younger brothers.

[20] At some point, the chronicle claims that the leading Islesmen sought assistance of Muirchertach, and petitioned him to provide a regent from his own kin to govern the kingdom until Lagmann's younger brother, Amlaíb mac Gofraid, was old enough to assume control.

[25] Although Domnall had earlier opposed Muirchertach over the kingship of Munster, he possessed strong familial connections with the Isles through his maternal descent from Echmarcach.

[27] In fact, the fifteenth- to sixteenth-century Annals of Ulster reveals that at least two apparent members of Echmarcach's family were killed less than a decade before in a repulsed invasion of Mann.

[32] This source not only corroborates Uí Briain intervention in the Isles,[33] but suggests that Domnall and the rest of the Meic Taidc faced significant opposition there,[34] possibly in the form of Lagmann's adherents.

[35] The chronicle credits Domnall with an oppressive three-year reign that ended when the leading Islesmen revolted against him, and drove him from the kingdom back to Ireland.

[39] Ingimundr's rationale for seating himself upon an island on the edge of the kingdom may have been due to the fact that he was unable to gain any authority on Mann itself.

[48] Although it may have also meant that Norwegian sovereignty in the Isles was recognised by the Irish,[49] it is also possible that Muirchertach intended to exert his own influence into the region through his new son-in-law.

[50] Unfortunately for Muirchertach, and his long-term ambitions in Ireland and the Isles, Magnús was slain in Ulster in 1103,[51] whereupon Sigurðr immediately repudiated his bride and returned to Norway.

[52] Although Muirchertach was able to regain control of Dublin, and still held considerable influence in the Isles, Magnús' death appears to have left a power vacuum in the region that he was unable to fill.

[70] Not long after his intrusion into the Isles—perhaps in 1113[72] or 1114[73]—Domnall appears to have been either driven out by force,[72] or drawn back to Ireland in an attempt to capitalise on Muirchertach's failing health.