Galileo Galilei
Andrea Sarti
Signora Sarti, Galileo's housekeeper and Andrea's mother
Ludovico Marsili, a rich young man
Signor Priuili, the Bursar of the University of Padua
Virginia, Galileo's daughter
Sagredo, Galileo's friend
Federzoni, a lens grinder, Galileo's collaborator
The Doge
Senators
Cosimo de' Medici, Grand Duke of Florence
Court Chamberlain
Older Lady in Waiting
Younger Lady in Waiting
Grnd Duke's Lackey
Two Nuns
Two Soldiers
Woman
Old Woman
Fat Prelate
Two Scholars
Two Monks
Two Astronomers
Very Thin Monk
Very Old Cardinal
Father Christopher Clavius, an astronomer
Little Monk
Cardinal Inquisitor
Cardinal Brberini, later Pope Urban VIII
Cardinal Bellarmin
Two Ecclesiastical Secretaries
Two Young Ladies
Filippo Mucius, a scholar
Signor Gaffone, Rector of the University of Pisa
Ballad Singer
Ballad Singer's Wife
Vanni, an iron-founder
Official
High Official
Individual
Monk, peasant, frontier guard, clerk, men, women, children