Ceretic Guletic of Alt Clut was a king of Alt Clut (modern Dumbarton) in the 5th century. He has been identified with Coroticus, a Britonnic warrior addressed in a letter by Saint Patrick. ...
... Ceretic's dates therefore depend on the conclusions of the vast scholarship devoted to discovering the floruit of St Patrick, but sometime in the 5th century is probably safe. Ceretic appears also in the Harleian genealogies of the rulers of Alt Clut, which list the names of his father (Cynloyp), grandfather (Cinhil) and great-grandfather (Cluim). It is from the latter source that we get his nickname, Guletic ("Land-holder"). In the Book of Armagh, he is called "Coirthech rex Aloo", "Ceretic, King of the Height [of the Clyde]"