He was about 33 when he succeeded his grandfather. Married to a cousin of Siward, Earl of Northumberland, he may have favoured southern ways and this is perhaps why he became unpopular with his subjects.
In 1040 he did march south to besiege Durham but he was beaten off, with heavy losses. Duncan attempted to impose his overlordship over Moray (an independent dynasty) by military force.
He was then twice defeated by the Earl of Orkney's son, Thorfinn, before being killed in battle by Macbeth, one of his commanders, near Elgin, Morayshire on 14 August 1040.
Image: The Duke of York hands over the Royal Warrant for the safe-keeping of the Stone of Destiny (or Scone) in the Great Hall in Edinburgh Castle in 1996. The stone was integral in the coronation of ancient Scottish kings.