Malcolm's mother is a mystery. John of Fordun, a Scottish chronicler from a few centuries after Malcolm, says she was a blood relative of Earl Siward, Earl of Northumbria, but this was probably a late attempt to tie Scottish royalty closer to possessions in England (but see below). An even later story suggests she was the daughter of a commoner and Malcolm was born out of wedlock.
Where was Malcolm when Duncan was killed by Macbeth? Malcolm was only about nine years old, but chieftains could have supported him. Tradition says that Duncan had sent his sons (besides Malcolm there was Donald and Máel Muire*) away for their safety; Fordun says Malcolm was sent to England to the court of Edward the Confessor.
Fordun writes that in 1054, Earl Siward of Northumbria invaded Scotland with the intent to install one Máel Coluim, son of the king of the Cumbrians, on the throne of Scotland. This Máel Coluim was identified as Malcolm III Canmore. William of Malmesbury agrees with this event, and says that Macbeth was killed by Siward. The problem with this is that Siward died two years before Macbeth. More recent scholars believe that Siward's Máel Coluim was a later Malcolm.
Other chroniclers of the time state that Macbeth was killed by Malcolm on 15 August 1057, but Macbeth was succeeded by his son Lulach (actually his step-son, born to his wife Gruoch—yes, "Lady Macbeth" did have her own name—from her first marriage), who was crowned in September. Lulach (whose nickname was Tairbith "The Unfortunate") was then killed by Malcolm in April 1058, who then became king shortly after.
It was common for Gaelic rulers to start their reigns with a show of strength by mounting an invasion somewhere. Malcolm's supposed close connection with England did not stop him from plundering Lindisfarne in 1061. This was far enough from the seat of English monarchy that it probably did not draw much attention. The local alderman of Northumbria at the time was Tostig Godwinson, but not only was he away on pilgrimage to Rome for recent offenses, but also he didn't care much for his people anyway.
Malcolm actually offered Tostig asylum at a time when Tostig needed a safe place. That, and other ties to English royalty, will be the subject for tomorrow.
*not this Máel Muire, however.
