Constantine III (A.K.A Causantín mac Cuilén) was king of Scots from 995 to 997. He was the son of Cuilean (A.K.A Cuilén mac Iduilb). John of Fordun calls him, in Latin, ‘Constantinus Calvus‘, which translates as Constantine the Bald.
Constantine became king upon the death of Kenneth II, supposedly killed by Finnguala, daughter of Cuncar, Mormaer of Angus, a killing with which Constantine is associated in several accounts. John of Fordun, perhaps confusing him with Eógan II of Strathclyde, known as “the Bald”, refers to Constantine the Bald. He reigned for eighteen months according to the Chronicle of the Kings of Alba.
John of Fordun writes that the day following the death of Kenneth II, Constantine the Bald, son of King Cullen usurped the throne. He had reportedly won the support of a number of nobles. The throne was also claimed by his cousin Malcolm II, son of Kenneth II, resulting in long-lasting division of the Scottish population, and conflict. Constantine III reigned for a year and a half [18 months], “continually harassed by Malcolm and his illegitimate uncle, named Kenneth, a soldier of known prowess, who was his unwearied persecutor, and strove with his whole might to kill him, above all others.”
The Annals of Tigernach report that he was killed in a battle between the Scots in 997. His death is placed by the Chronicle at Rathinveramond at the mouth of the Almond where it meets the River Tay near Perth. This appears to have been a royal centre, close to Scone and Forteviot, as Domnall mac Ailpín is said to have died there in 862. His killer is named as Cináed mac Maíl Coluim, probably in error for either Cináed mac Duib, who became king on Constantine’s death, or perhaps for Máel Coluim mac Cináeda.
Constantine is not known to have any descendants and he was the last of the line of Áed mac Cináeda to have been king.