Cador (Latin: Cadorius) is a legendary Duke of Cornwall, known chiefly through Geoffrey of Monmouth's pseudohistorical Historia Regum Britanniae and previous manuscript sources such as the Life of Carantoc. In Welsh genealogical records, he appears as Cado (Cadwr), the son of Cornish king Geraint. Early sources present him as a relative of King Arthur, though the details of their kinship are usually left unspecified.Circa 1100 from Cotton Vespasian xiv.