Corineus or Corin, was a warrior was said to be descended from the heroes of the Trojan Wars. He was the second in command of Brutus the Trojan, legendary founder of Britain, and accompanied him to England. His exploits are described initially in the “Historia Regum Britanniae” by Geoffrey of Monmouth. John Milton also described the exploits of Brutus and Corineus, although later historians deem the latter to be a purely legendary figure.
Milton states that Corineus used a battle axe with which he had previously performed marvels. He slew the giant Gogmagog, the greatest of the giants inhabiting Cornwall and the south west, by hurling him from a cliff near Totnes in Devon. For this feat he was rewarded with the gift of the south western horn of Britain, which from then on was known as Corinea or Cornovia, eventually becoming Cornwall. Similarly, the name of Britain is said to derive from the name of his commander, Brutus.
Apparently, this particular corner of Britain was given to Corineus as the greatest number of monsters and the most enormous giants were said to lurk in the caves and rocks of the far west corner. Corineus had already proved that he could deal with this kind of problem.