Fragan was a 5th-century aristocrat and prince from Scotland who is recognized as a saint. Originally from Great Britain, he moved to the region of Armorica to spread the Christian faith. He eventually settled in the Sang River valley, where he established the castle of Lesguen. Throughout his life, he was involved in both religious missions and military defense, notably leading a small group of soldiers to defend against pagan pirates at the battle of Lochrist.