Cybi was a 6th-century priest and bishop who operated across Cornwall and North Wales. Born to a Cornish noble, he reportedly traveled to the Holy Land as a young man before returning to find himself the heir to the Cornish throne. He declined the kingship to dedicate his life to religious service, traveling his father's former lands to preach and establish churches. His missionary work eventually led him to Wales, where he founded significant religious sites and monasteries.