Humbled, Peter reevaluated his motivations (his bishop-uncle had secured the cathedral post for him) and started down a new path. He became a Dominican priest and proved to be a most effective preacher. He spent much of his time as court chaplain, and attempted to exert positive influence on the behavior of members of the court. After King Ferdinand III and his troops defeated the Moors at Cordoba, Peter was successful in restraining the soldiers from pillaging and persuaded the king to treat the defeated Moors with compassion.
After retiring from the court Peter devoted the remainder of his life to preaching in northwest Spain. He developed a special mission to Spanish and Portuguese seamen. He is the patron of sailors.
Peter Gonzalez died in 1246 and was beatified in 1741.