A member of the Uí Ímair dynasty, his ancestors also included Amlaíb Cuarán and Gormflaith, who were influential in medieval Ireland.
[8] In 1027, after the death of Máel Sechlainn II in 1022 and the chaos which accompanied the subsequent bids for the High Kingship by the Irish princes, Sigtrygg Silkbeard was forced to make a new alliance with the men of Brega.
[10] The army of Sigtrygg and Donnchad was defeated by the men of Meath under their king, Roen Ua Mael Sechlainn.
[10][11] Sigtrygg rallied to the fight again, and fought a battle at Lickblaw (near Castlepollard, Westmeath) where Donnchad and Roen were slain.
[12] The incident illustrates the importance of ransoming noble captives, as a means of political manipulation, increasing one's own revenues and exhausting the resources of one's foes.