And therewith Sir Tristram mounted upon his horse, and there he met with King Arthur, and he gave him such a buffet upon the helm with his sword that King Arthur had no power to keep his saddle. And then Sir Tristram gave the King of Northgalis King Arthur’s horse: then was there great press about King Arthur for to horse him again; but Sir Palomides would not suffer King Arthur to be horsed again, but ever Sir Palomides smote on the right hand and on the left hand mightily as a noble knight.

Malory's Le Morte d'Arthur