http://en.wikipedia.org/wiki/Malcolm_I_of_Scotland

Máel Coluim mac Domnaill ,[1] anglicised as Malcolm I, and nicknamed An Bodhbhdercc, "the Dangerous Red"[2] was king of Scots, becoming king when his cousin Constantine II abdicated to become a monk. He was the son of Donald II .
In 945 Edmund the Elder, King of England, having expelled Olaf Sihtricsson from Northumbria, devastated Cumbria and blinded two sons of Domnall III , king of Strathclyde. It is said that he then "let" or "commended" Strathclyde to Malcolm in return for an alliance.[3] What is to be understood by "let" or "commended" is unclear, but it may well mean that Malcolm had been the overlord of Strathclyde and that Edmund recognised this while taking lands in southern Cumbria for himself.[4]
The Chronicle of the Kings of Alba says that Malcolm took an army into Moray "and slew Cellach". Cellach is not named in the surviving genealogies of the rulers of Moray, and his identity is unknown.[5]
Malcolm appears to have kept his agreement with the late English king, which may have been renewed with the new king, Edmund having been murdered in 946 and succeeded by his brother Edred. Eric Bloodaxe took York in 948, before being driven out by Edred, and when Olaf Sihtricsson again took York in 949–950, Malcolm raided Northumbria as far south as the Tees taking "a multitude of people and many herds of cattle" according to the Chronicle.[6] The Annals of Ulster for 952 report a battle between "the men of Alba and the Britons [of Strathclyde] and the English" against the foreigners, i.e. the Northmen or the Norse-Gaels. This battle is not reported by the Anglo-Saxon Chronicle, and it is unclear whether it should be related to the expulsion of Olaf Sihtricsson from York or the return of Eric Bloodaxe.[7]
The Annals of Ulster report that Malcolm was killed in 954. Other sources place this most probably in the Mearns, either at Fetteresso following the Chronicle, or at Dunnottar following the Prophecy of Berchán. He was buried on Iona.[8] Malcolm's sons Dub and Kenneth were later kings.