A former holy cleric who had an insatiable appetite for human flesh, Aldrich's growing strength eventually transformed him into an abomination and he became a Lord of Cinder. While thinking on the fading First Flame, he began to have visions of a "coming age of the deep sea", from which he founded the Church of the Deep, utilizing a darkness, far beyond that of Humanity, known as the Deep. The Church of the Deep was founded to serve Aldrich and provide a steady stream of sacrifices, overseen by Pontiff Sulyvahn and Archdeacon Royce.
After Aldrich was revived as a Lord of Cinder, he began dreaming of the Old Gods and sought to devour them. Sulyvahn travelled with him to Anor Londo and managed to capture Dark Sun Gwyndolin who sacrificed himself to save his sister, Company Captain Yorshka. She managed to evade capture, but Aldrich devoured Gwyndolin.