Maelcon, often known as Maelcon the Usurper, was the eldest son of the Cruarch of Alba and Foclaidha of the Tarbh Cró. In keeping with Alban matrilineal succession, Maelcon was not his father's heir. Instead, that honor went to his cousin, Drustan mab Necthana, the son of the Cruarch's sister Necthana. Despite this long-standing tradition, both Maelcon and his mother coveted Drustan's inheritance for themselves.
Along with his father and the rest of their family, Maelcon briefly visited Terre d'Ange in a rare crossing allowed by the Master of the Straits, whose powers over wind and sea long kept their nation isolated. There, D'Angeline Admiral Quintilius Rousse observed that he was a large, strapping young man who appeared displeased to be passed over for his cousin. Eventually Maelcon slew his father and stole his throne, driving Drustan, Necthana, and Necthana's three daughters into exile to western Alba, where they took refuge with the Dalriada. Later, it was exposed that Maelcon and Foclaidha conspired together with Lyonette de la Courcel de Trevalion to put their sons on the Alban and D'Angeline thrones in place of their cousins, the rightful heirs.
Maelcon ruled as Cruarch in Alba for several years, though he was not loved by the Commonfolk. This persisted until Drustan, with the aid of the Dalriada and a small contingent of D'Angelines, rose up against him and overthrew him. Maelcon was slain by his cousin at the Battle of Bryn Gorrydum and his head was nailed above the gates of Bryn Gorrydum.