Despite grand tales of retrieving the Holy Grail, which come later on in Arthurian literature, the original Welsh Arthur had a different quest.

In Culhwch ac Olwen, Arthur and his men pursue a giant boar in order to retrieve the golden comb and shears from between its ears. Ah, what nobler quest could one ask for? Not only must they battle the boar, Twrch Trwyth, but they must fight its deadly piglets, as well.

Arthur sends his men to Ireland to see if the boar is there, and if it has the treasures between its ears. The text reads: "That the boar was there was certain; it had already destroyed a third of Ireland."

Later on the text reads: "Dogs attacked the boar from all directions, and the Irish battled it throughout the day until night fell; despite that, a fifth of Ireland was destroyed by it." (Somehow these fractions add up. Let's see - a third plus a fifth - is that a majority of Ireland yet?)

Arthur does not kill the boar -- it lumbers into the sea, its sides bristling with spears, to hunt another day.