Constantine was born in 971, the son of King Culen of Scotland, the same year that Kenneth II overthrew and killed his father. Kenneth spared Constantine’s life and raised him at court, unaware of the young man’s true ambitions. From an early age, Constantine coveted the throne, and by 995 he had assembled supporters and begun plotting Kenneth’s murder.

To achieve this, Constantine courted Lady Finella, whom Kenneth loved, deceiving her into believing his affection was genuine. He persuaded her to meet the king privately in the drying house to declare her wish to marry Constantine instead. There, Constantine ambushed and murdered Kenneth, seizing the throne. To strengthen his claim, he planned to force Princess Katharine into marriage, holding the gargoyle eggs in her care hostage. With the help of the Magus, Finella, Tom, and Mary, Katharine and the eggs escaped to Avalon. Mary and Finella then took possession of the Grimorum Arcanorum to prevent Constantine and his sorcerers from reaching Avalon.

Furious at their escape, Constantine resolved to exterminate all gargoyles in Scotland, influenced by his father’s earlier defeat through an alliance with the Wyvern Clan. While his forces hunted Mary and Finella, Constantine forged alliances to secure his rule, joining with Irish forces and moving against the armies of Kenneth III, Maol Chalvim, and Findlaech. He brought Maíl Brigti and Gillecomgain into his service and allied himself with the sorcerer Brother Valmont.

As war approached, Constantine shaved his head and painted it with black war paint, marking three scars across his face and eyes on the back of his head, a fearsome appearance that would later inspire the Hunters. During the Battle of Rathveramoen, Constantine dueled Kenneth III, threatened Kenneth’s son Bodhe, and urged Gillecomgain to become a Hunter for his king. Constantine was ultimately slain in the battle, but not before bitterly warning Kenneth III of Maol Chalvim’s own ambitions to claim the throne.