Pendragon

Uther Pendragon was the father of King Arthur.

Source: tatoeba (2720481)

[I]n the reign of Henry the Second, a body happening, by chance, to be dug up near Glastonbury Abbey, without any symptoms of putrefaction or decay, the Welch, the descendants of the Ancient Britons, tenacious of the dignity and reputation of that illustrious hero [King Arthur], vainly supposed it could be no other than the body of their justly-boasted Pen-Dragon; and that he had been immured in that sepulchre by the spells of some powerful and implacable inchanter.

Source: wiktionary

The regal dominion, then, held by the sovereigns of Britain in these ages seems most properly described as an elective monarchy made hereditary; or, to take the converse of the proposition, as a hereditary monarchy requiring to be confirmed at the succession of each monarch by a popular election. […] There was this essential difference, as now in the case of the kings paramount, or pendragons^* of Britain, traces of succession by descent are noticeable. […] Thus we find in [Julius] Cæsar’s Commentaries, Gaulish Wars, vii, 4, that Celtillus, a pendragon or leader general of the Gauls, lost his life because he had endeavoured to change his delegated power into an “imperium,” that is, to make it more permanent and settled. [Footnote: ^* It is common to call the sovereigns of Britain, like Cassibelan, Uther, Arthur, and others, ‘pendragons,’ because Uther Pendragon, one that was famous among them, was so called.[…]]

Source: wiktionary

At last he got his breath and answer'd, 'One, / One have I seen—that other, our liege lord, / The dread Pendragon, Britain's king of kings, / Of whom the people talk mysteriously, / He will be there—then were I stricken blind / That minute, I might say that I have seen.'

Source: wiktionary