Welsh lore often presents a very different version of Arthur than is commonly found in most post-Geoffrey Arthurian literature. I ran across this the other day while browsing Bromwich’s Trioedd Ynys Prydein:
Traid 20 W: Three Red Ravagers of the Isle of Britain
- Rhun son of Beli;
- and Lle(u) Skilful Hand,
- and Morgan(t) the Wealthy,
But there is one how was a Red Ravager greater than than all three: Arthur was his name. For a year neither grass nor plants used to spring up where one of the three would walk; but where Arthur went, not for seven years. (p. 20)
You may be wondering who these other men were? Lleu Skilful hand is the Celtic god Lleu who was historicized into the early medieval period. The mythology of his story is told in the Mabinogion. He was historicized as Lot(h) of Lothian. Not without reason as as early as Y Gododdin, parts of which date to the seventh century, refer to Dun Edyn (Edenburgh) as Lleu’s fortress or Lleu’s rock. Rhun ap Beli is more insecure as both are common names. Morgan(t) the Wealthy is probably intended to be the Morgant who is reputed to have killed Urien Rheged in the Historia Brittonum.
As for the red ravagers, it is worth noting that excessive amounts of blood is toxic to plant life (maybe because of the iron content?). This would have the grizzly consequence of battlefield dead remaining visible for longer than you might imagine if they were left unburied and there was enough blood spilled on the ground.
Triad 54: Three Unrestrained Ravagings of the Isle of Britain:
- The first of them (occurred) when Medrawd came to Arthur’s Court at Celliwig in Cornwall,; he left neither food nor drink in the court that he did not consume. And he dragged Gwenhwyfar from her royal chair, and then struck a blow upon her.
- The second Unrestrained Ravaging (occurred) when Arthur came to Medrawd’s court. He left neither food nor drink in the court.
- (And the third Unrestrained Ravaging (occurred) when Aeddan the Wily came to the court of Rhydderch the Generous at Alclud (= Dumbarton); he left neither food nor drink nor beast alive.) (p. 147).
The Arthur of the Welsh is not much like the courtly Arthur of later romance who works through proxies. He is not even much like Geoffrey of Monmouth’s Arthur. To the Welsh, he is the Red Ravager, the great warlord.
Rachel Bromwich, trans.  Trioedd Ynys Prydein: The Welsh Triads. Cardiff: University of Wales Press.