But for me, I always think of Sir Thomas Malory's work this day.
“The king stablished all his knights, and gave them that were of lands not rich, he gave them lands, and charged them never to do outrageousity nor murder, and always to flee treason; also, by no mean to be cruel, but to give mercy unto him that asketh mercy, upon pain of forfeiture of their worship and lordship of King Arthur for evermore; and always to do ladies, damosels, and gentlewomen succor upon pain of death. Also, that no man take no battles in a wrongful quarrel for no law, ne for no world’s goods. Unto this were all the knights sworn of the Table Round, both old and young. And every year were they sworn at the high feast of Pentecost.” (Le Morte d'Arthur, pp 115-116)