He wrote <em>"Il Cortegiano"</em> ("The Courtier") and it was his most important work.
In the manuscript, he exposes the ways in which Gentlemen has to behave in several areas; from being skilled with weapons, to writing letters correctly and also on how to properly address to other people, especially women.
It refers to a model of a Gentleman that responds to the concerns, ideals and visions of the time(Renaissance).