Cináed mac Duib (Kenneth III) was King of Scots from 997 to 1005. He was the son of Dubh (A.K.A Dub mac Maíl Coluim). Kenneth was known as the ‘Donn’ meaning the brown-haired. Kenneth III became king on the murder at Rathinveramon of his predecessor and cousin, King Constantine III.
The two rival branches of the family continued to fight for the right to the throne. This fierce rival continued for generations and was a direct result of the tanistry system of inheritance, which then prevailed in Scotland where the family would vote on who would be the next King.
Kenneth had a son called Giric, to confirm him as the next King in line Kenneth made Giric a joint King or legh-righ. He was trying to go against the laws of tranisty and ensure that Giric was his successor. Unfortunately for Kenneth this wasn’t to pan out and his successor was Malcolm II who had his own plans on how to secure his own bloodline.
Kenneth invaded Northumbria, asserting what he saw as his hereditary right, taking the Earl of the province back to Scotland as his prisoner.
The only event reported in Kenneth’s reign is the killing of Dúngal mac Cináeda by Gille Coemgáin mac Cináeda, by the Annals of the Four Masters s.a. 999. It is not certain that this refers to events in Scotland, and whether one or both were sons of this Kenneth, or of Cináed mac Maíl Coluim, or some other person or persons, is not known. Kenneth was killed in battle at Monzievaird in Strathearn by his cousin Malcolm II in 1005.
Malcolm II took to the throne and proceeded to hunt down and kill all of Kenneth II’s male descendants. However, he did not succeed and the line of Kenneth III was not totally extinguished. His grand-daughter Gruoch ngen Boite meic Cináeda, (Shakespeare’s Lady Macbeth) had a son called Lulach from her first marriage to Gillacomgain, Mormaer of Moray. Lulach succeeded to the throne on the death of his mother’s second husband, King MacBeth. The meic Uilleim, descendants of William fitz Duncan by his first marriage, were probably descended from Kenneth and the Clann Mac Aoidh or Clan Mackay claim descent from Kenneth III through Lulach’s daughter.