Ahh, historical symmetry. On August 15 (or maybe 14, it’s hard to say for sure), 1040, King Duncan I was killed in battle against his first cousin, Macbeth, who promptly took the throne of Scotland. Exactly 17 years later, Duncan’s son, Malcolm, returned to Scotland and killed Macbeth, bringing the throne back into his own family.
Unlike the way he was depicted in the Shakespeare play, Duncan was not an elderly king smothered in his bed by a power-hungry rival. It’s believed he came to the throne at a very young age, and that Macbeth wielded the real power. Unfortunately, young kings grow up, and Duncan grew up to lead an ill-fated siege of Durham, which did not go well at all. The following year, he invaded Macbeth’s domain of Moray, and that’s where he was killed—by his own men, no less, under Macbeth’s leadership.
Duncan’s two young sons were allegedly hidden away by their mother, possibly in Atholl. There, they bided their time and reached puberty. After that, they were ready to retake the throne. Macbeth, meanwhile, did ok as king for a while, but then he got involved in the squabbles between the Earl of Wessex and Edward the Confessor in England, which seemed to have led to a downward slide in Macbeth’s popularity. He retreated to Aberdeenshire, where Malcolm met him, and they clashed in the Battle of Lumphanan. Not much is known about the battle itself, aside from the fact that Macbeth defintely lost. A rock known as Macbeth’s Stone is said to be the one upon which he was beheaded, on August 15, 1057.