For Chivalry, I think there are two good choices. One is to trim the existing quote down to the last sentence.
The other is the Civ5 quote.
I think I'm leaning more toward the Malory for being more time-appropriate.
"The age of chivalry is never past, so long as there is a wrong left unredressed on earth." - Charles Kingsley
"Whoso pulleth out this sword of this stone and anvil, is rightwise king born of all England." - Malory