The following lines are from the Stanzaic Morte Arthur (one of the sources of Morte Darthur). King Arthur is in battle against Lancelot over the affair Lancelot has had with Guinevere.
"In all the feld that ilke tide
Might no man stand Launcelot again,
And sithen as fast as he might ride
To save that no man sholde be slain.
The king was ever ner beside
And hew on him with all his main
And he so courtais was that tide
O dint that he nolde smite again."
That is to say,
In all the field that day
No man could stand against Lancelot,
And he (Lancelot) rode as fast as he could
To make sure that nobody was killed
The king (Arthur) was ever near behind him
And hewed at Lancelot with all his strength
But so courteous was Lancelot that day
That he would not strike Arthur in return
On one hand, this passage shows Lancelot's reluctance to fight against Arthur, but it also tells in very few words the waning of Arthur's physical strength. As a young man, Arthur had legendary battles with knights such as Pellinore and Accolon, but here he cannot even faze Lancelot. King Arthur's physical decline mirrors the decline of his court, but Lancelot's continued respect for his lord shows that the chivalry of Arthur's reign outlasts man and table and is the real legacy that Arthur leaves.