Cassio is a Florentine gentleman and is chosen by Othello to be his Lieutenant. Iago gets him fired for drunken brawling and then gets him to ask Desdemona to help reinstate him as lieutenant. Cassio makes Iago's lies about him plausible by his pleasant Venetian manners and Othello's mis-taken interpretation of his disrespectful treatment of his girlfriend, the prostitute Bianca. Venetian orders arrive naming him as the new governor of Cyprus. Cassio survives the attack of Roderigo (set on by Iago) and takes over as governor of Cyprus at the end.

Bianca returns the handkerchief to Cassio, played by Derek Jacobi in the National Theater's 1964 production, directed by John Dexter. Angus McBean, Harvard Theatre Collection.