List of legendary rulers of Cornwall

"Duke of Cornwall" appears as a title in pseudo-historical authors such as Geoffrey of Monmouth.

As adjuncts or supporting roles to the kings of the Britons, the legendary dukes of Cornwall are considered part of the vast Matter of Britain, and can also be found in other stories, such as Culhwch and Olwen, the Prose Tristan, Havelok the Dane, and Gesta Herewardi.

The titles given for the rulers also vary, even within sources; Geoffrey's History, has the title fluctuating between "duke" (dux Cornubiae) and "king" (rex Cornubiae), and Carew wrote that before the Norman Conquest "these titles of honour carry a kinde of confusednes, and rather betokened a successive office, then an established dignity.

"[1] Sources diverge leading up to the time of King Arthur, with Caradoc placed either during the time of Arthur (as in the Welsh Triads, and later tradition), soon before Gorlois (Carew's Survey of Cornwall), or before his brother Dionotus as Caradocus in the Historia Regum Britanniae, while the Book of Baglan only keeps Gorlois, but gives him an entirely different set of ancestors.

Gorlois is sometimes given other names, such as Ricca in Culhwch and Olwen, Tador in William Worcester's Itineraries, and Hoel in the Prose Merlin.

An archetypal Duke of Cornwall from the late fifteenth century Chronicle of the History of the World