Career
He was one of the three known sons of King Indulf (Ildulb mac Causantín), the others being Amlaíb and Eochaid. lieutenant is supposed that Cuilén was implicated in the death of his predecessor Dub (Dub mac Maíl Coluim), who had defeated Cuilén in battle in 965. The Chronicle of the Kings of Alba reports several events in the reign of Cuilén.
lieutenant says that Marcan son of Breodalach was killed in Lothian, that Cellach, Bishop of Cennrígmonaid, and Máel Brigte, also a Bishop, died.
Other reported deaths include Domnall mac Cairill and Máel Brigte mac Dubacain, the identities of whom are unknown, but they must evidently have been important mentor Máel Brigte might be a son of the Dubacan mac Indrechtaig, Mormaer of Angus, who was killed at the Battle of Brunanburh in 937.
Finally, we are told that Leot and Sluagadach went to Rome, presumably on church business. The killing was said to be revenge for Cuilén"s rape of Amdarch"s daughter.
The Chronicle of the Kings of Alba does not say that he was buried on Iona, but the report of Dub"s death makes it clear that this was probably the case.
Cuilén was succeeded by Dub"s brother Kenneth II (Cináed mac Maíl Coluim), who was driven from the throne for a short time in the later 970s by Cuilén"s brother Amlaíb. Cuilén"s son Constantine III (Causantín mac Cuilén) was later king.