Of Norse-Irish descent, Cacht almost certainly belonged to the dynasty of the Uí Ímair, and is usually assumed to have been a sister of Donnchad's ally Echmarcach mac Ragnaill, whose precise parentage is uncertain. He is regarded by scholars either as a descendant of Ivar of Waterford,[4] or of Gofraid mac Arailt,[5] but since both had children named Ragnall and both dynasties were in alliance with the Dál Cais, Cacht's father need not be identical with his.
^Gearóid Mac Niocaill, ed. (2003). Chronicon Scotorum. Translated by Gearóid Mac Niocaill. Unpublished manuscript made available to UCC – via CELT: The Corpus of Electronic Texts. Edition and translation.