Portormo's artistic skills are obvious in this portrait in the National Gallery of Art. His style is a brilliant synthesis of fantasy and acute observation. Here the balance is tilted towards visible reality, but the large caped torso squeezed so close to the picture plane it brushes the sides and the Monsignor seems about to bump his head on the frame.  The viewer is drawn to the left hand and his famous book.

Giovanni della Casa, known as "Il Monsignore", became a cleric in Florence after studying law in Bologna. In Rome, he was close to many prominent personalities, including Cardinal Alessandro Farnese, who appointed him to various offices in Florence. In 1555 he was made Secretary of State of the Holy See and he died in Rome in 1556. He is most famous for his treatise Galateo, which remains a milestone in Italian literature and still known as a reference for polite behavior and courtesy.