Monarchs of Cornwall

Husband of Iseault in Arthurian legend

thumb|Igraine and Gorlois in [[Władysław T. Benda's illustration for Uther and Igraine by Warwick Deeping (1903). In much of modern Arthurian tradition (a prominent example is 1983's The Mists of Avalon), he is portrayed as a jealous and abusive husband]]

Cador () 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 Carannog. In Welsh genealogical records, he appears as Cado (), 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.

Corineus, in medieval British legend, was a prodigious warrior, a fighter of giants, and the eponymous founder of Cornwall.

Saint Cybi (Welsh), or Cuby (Cornish), was a 6th-century Cornish bishop, saint, and, briefly, king, who worked largely in Cornwall and North Wales: his biography is recorded in two slightly variant medieval 'lives'.

king

Caradocus (middle Welsh: Karadawc), according to Geoffrey of Monmouth's Historia regum Britanniae, a pseudohistorical account of the kings of the Britons, was the duke of Cornwall under the reign of Octavius, who became king of Cornwall and died during the Emperor Magnus Maximus' reign.

thumb|Dionotus, Saint Ursula's father, in a 1495 painting by [[Vittore Carpaccio]] Dionotus was a legendary king of Cornwall in Geoffrey of Monmouth's Historia regum Britanniae, an account of the rulers of Britain based on ancient Welsh sources and disputed by many historians. Dionotus succeeding his brother Caradocus, and was regent of Britain during the campaigns in Gaul of Emperor Magnus Maximus. The curious thing about this king is that the Welsh chronicles, which parallel most of Geoffrey of Monmouth's book, do not mention this king by name. However, Geoffrey uses Latin versions of Welsh