Donnchad mac Crínáin (Duncan) was king of Alba. He was son of Crínán, hereditary lay abbot of Dunkeld, and Bethóc, daughter of king Máel Coluim mac Cináeda.
Unlike the “King Duncan” of Shakespeare’s Macbeth, the historical Donnchad appears to have been a young man. He followed his grandfather Máel Coluim as king after the latter’s death on 25 November 1034, without apparent opposition. He may have been Máel Coluim’s acknowledged successor or tánaise as the succession appears to have been uneventful. Earlier histories, following John of Fordun, supposed that Donnchad had been king of Strathclyde in his grandfather’s lifetime, ruling the former Kingdom of Strathclyde as an appanage. Modern historians discount this idea.
Another claim by Fordun, that Donnchad married a sister of Earl Siward of Northumbria, appears to be equally unreliable. An earlier source, a variant of the Chronicle of the Kings of Alba (CK-I), gives Donnchad’s wife the Gaelic name Suthen. Whatever his wife’s name may have been, Donnchad had at least two sons. The eldest, Máel Coluim mac Donnchada was king from 1057 to 1093, the second Domnall Bán was king afterwards. Máel Muire of Atholl is a possible third son of Donnchad, although this is uncertain.
In 1039, Donnchad led a large Scots army south to besiege Durham, but the expedition ended in disaster. Donnchad survived, but the following year he led an army north into Moray, traditionally seen as Mac Bethad’s domain. There he was killed, at Pitgaveny near Elgin, by his own men led by Mac Bethad, probably on 15 August 1040.