Cuilean (A.K.A Cuilén mac Iduilb) was king of Alba from 967 to 971. He was one of three known sons of Indulf (A.K.A Idulb mac Causantín), the others being Amlaíb and Eochaid. Cuilean had previously missed out on the throne because the laws of Tannistry meant that the crown had gone to King Dubh (Tannistry is in effect a vote by the senior members of the extended family on who will take the crown). Cuilean believed himself to be the rightful heir and was implicated in the King’s murder, which happened in Forres in 967. King Dubh had previously defeated Cuilean in battle in 965.
The Chronicle of the Kings of Alba reports several events in the reign of Cuilean. It says that Marcan son of Breodalaig (or Breodalach) was killed in the Church of St Michael (in St Andrews), 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 men. 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.
In 971 Cuilean, along with his brother Eochaid, were killed in a hall-burning in Lothian by Amdarch, king of Strathclyde. The killing was said to be revenge for Cuilean’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 likely the case.
Cuilean was succeeded by Dubh’s brother Kenneth II (A.K.A Cináed mac Maíl Coluim), who was driven from the throne for a short time in the later 970s by Cuilean’s brother Amlaíb. Cuilean’s son Constantine was later king becoming Constantine III.