Sandde, King of Ynys Manaw
(Born c.AD 685)
(Welsh: Sandde; Latin: Xanthus; English: Sant)

Sandde ab Alcwn was the 3x great grandson of King Llywarch Hen and heir to his lost Kingdom of South Rheged. It was Sandde who transferred his family from Powys to Ynys Manaw (Isle of Man) when he married, Celemion, sister and heiress of its King, Iudgual, in the mid-8th century. He soon became King of the island in right of his wife and was later succeeded by their son, Elidyr, and then his grandson, Guriat.