 He is thought to be the first Welsh ruler to visit Rome after the healing of the breach between the Welsh branch of the Celtic Church and Rome over the date of Easter.Cyngen raised a pillar, originally a round-shafted cross, in memory of his great-grandfather Elisedd ap Gwylog which stands near the later abbey of Valle Crucis.This memorial had a lengthy inscription and is known as the Pillar of Eliseg owing to a typographical mistake by the original carver.