Medieval Arthurian legend
Of Arthur and of Merlin
14th century Middle English. National Library of Sotland MS Advocates 19.2.1, the Auchinleck Manuscript; Lincoln's Inn Library, Hale MS 150.
Then the white dragon reared up and the fight began anew.
Everybody ran for their lives! The dragons rose from their den and took no notice of the men who were fleeing but set upon one another viciously, breathing flames so fiercely that all the vegetation about them was burned to ashes. They bit one another and slashed with claw and tail. The earth shook beneath them, so fierce was the battle, and even the weather changed. Storms rolled in as they bit and grappled and clawed and breathed fire at one another; they rose and fell and fought as though they were insane. They fought for almost a day without any rest, until the red dragon began to gain the upper hand and drove the white dragon into a valley, but here they both rested for a while. Then the white dragon reared up and the fight began anew. The white dragon drove the red up onto the high ground once more and here he got the better of the red dragon, he threw it to the ground and by the strength of his fiery breath, he burned the red dragon to ashes. There was nothing left of it. Then the white dragon flew away, and no one knows where, for no one has ever seen it since.