Caradocus

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.

Caradocus was the Duke of Cornwall during the reign of Octavius. It was he who suggested to Octavius that he should wed his daughter to Maximus and unite Britain with Rome through that union. When Octavius agreed to the idea, Caradocus sent out his son, Mauricius, to Rome as to deliver the message to Maximus. Conan Meriadoc, the king's nephew, did not approve and nearly attacked Maximus when he landed near Southampton. Only when Caradocus arrived was peace restored. They dispersed and Octavius handed Maximus the kingship and retired, as Caradocus rallied behind Maximus.