A man’s ticket to fortune was no longer being the baddest knight in the area but making a pilgrimage to the king’s court and currying favor with him and his entourage. The court, basically a government bureaucracy, had no use for hotheads and loose cannons, but sought responsible custodians to run its provinces. The nobles had to change their marketing. They had to cultivate their manners, so as not to offend the king’s minions, and their empathy, to understand what they wanted. The manners appropriate for the court came to be called “courtly” manners or “courtesy.” The etiquette guides, with their advice on where to place one’s nasal mucus, originated as manuals for how to behave in the king’s court.
Steven Pinker in “The Better Angels of Our Nature: Why Violence Has Declined”; page 75