Ildulb mac Causantín, anglicised as Indulf, nicknamed An Ionsaighthigh, "the Aggressor" (died 962) was king of Scots from 954. He was the son of Constantine II (Causantín mac Áeda); his mother may have been a daughter of Earl Eadulf I of Bernicia, who was an exile in Scotland.
John of Fordun and others supposed that Indulf had been king of Strathclyde in the reign of his predecessor, based on their understanding that the kingdom of Strathclyde had become a part of the kingdom of Alba in the 940s. This, however, is no longer accepted.
The Chronicle of the Kings of Alba says: "In his time oppidum Eden", usually identified as Edinburgh, "was evacuated, and abandoned to the Scots until the present day." This has been read as indicating that Lothian or some large part of it, fell to Indulf at this time. However, the conquest of Lothian is likely to have been a process rather than a single event, and the frontier between the lands of the kings of Alba and Bernicia may have lain south and east of Edinburgh many years before Indulf's reign.
Indulf's death is reported by the Chronicon Scotorum in 962, the Chronicle of the Kings of Alba adding that he was killed fighting Vikings near Cullen, at the Battle of Bauds. The Prophecy of Berchán, however, claims that he died "in the house of the same holy apostle, where his father [died]", that is at the céli dé monastery of St Andrews. He was buried on Iona.
Indulf was succeeded by Dub (Dub mac Maíl Coluim), son of his predecessor. His sons Cuilén and Amlaíb were later kings. Eochaid, a third son, was killed with Cuilén by the men of Strathclyde in 971.
- ^ "Ildulb" is an Old Irish name derived from either the Old Norse name Hildulfr or the Old English name Eadwulf. It occurs in various contemporary Gaelic forms, such as Iondolbh, found in the Duan Albanach. "Ildulb" was later rendered "Indulf" under Old French influence. Ildulb is used because by some historians because it correctly represents the name Hildulfr in Gaelic orthography; Eadwulf would perhaps be Idulb, hence that form is also used sometimes. The name never came into wider use in the Scottish world, or the Gaelic world more generally, and has no modern form. Walker, p. 97.
- ^ Skene, Chronicles, p. 94.
- ^ It is known a sister of Indulf married Olaf III Guthfrithson (Amlaíb mac Gofraidh) of the Uí Ímair and one of Indulf's sons was named Amlaíb. Walker suggests that Indulf's mother may have been a daughter of Earl Eadwulf, who was an exile in Alba. Eadwulf is rendered Ettulb in the Annals of Ulster, s.a. 913, where his death is reported. Walker, p. 97
- ^ Duncan, pp.40–41.
- ^ Duncan, p. 24; Early Sources, p.468, note 4.
- ^ Duncan, p. 247–25; Smyth, pp. 221–223.
- ^ Early Sources, pp. 468–471; Duncan, p. 20 follows the Chronicle.
- Anderson, Alan Orr, Early Sources of Scottish History AD 500–1286, volume 1. Reprinted with corrections. Paul Watkins, Stamford, 1990. ISBN 1-871615-03-8
- Duncan, A.A.M., The Kingship of the Scots 842–1292: Succession and Independence. Edinburgh University Press, Edinburgh, 2002. ISBN 0-7486-1626-8
- Smyth, Alfred P. Warlords and Holy Men: Scotland AD 80-1000. Reprinted, Edinburgh: Edinburgh UP, 1998. ISBN 0-7486-0100-7
- Walker, Ian W., Lords of Alba: The Making of Scotland. Sutton, Stroud, 2006. ISBN 0-7509-3492-1