Born in Rome in a noble family. Brother of the better-known Virginio (1596-1624) to whom Galileo Galilei (1564-1642) addressed Il Saggiatore [The Assayer] (Rome, 1623) in the form of a letter. Ferdinando Cesarini corresponded with Benedetto Castelli (1577/8-1643), who described the Galilean thermoscope to him in a letter of September 20, 1638.