Who wrote the book 'The Courtier' describing Renaissance courtly behavior?

Baldassare Castiglione wrote The Book of the Courtier, a Renaissance guide to courtly behavior and education.

Known in Italian as Il Libro del Cortegiano, the book was published in Venice in 1528 by the Aldine Press. It takes the form of an imagined conversation among members of the court of Urbino, where participants debate the qualities of an ideal courtier and, later, an ideal court lady.

Castiglione’s ideal courtier needed more than good manners. He was expected to combine noble character, physical skill, military ability, knowledge of the humanities, musical and artistic accomplishments, eloquence, and social grace. The book also presents the influential idea of sprezzatura: performing difficult actions with an appearance of effortless ease.

The work became one of the most influential courtesy books in Europe. Sir Thomas Hoby’s English translation appeared in 1561 and helped shape ideas about the cultivated gentleman in Elizabethan England. Erasmus, Thomas More, and Machiavelli were also important Renaissance writers, but none wrote The Book of the Courtier.