• Willam Walton. Opera in three acts. 1954.
• Libretto by Christopher Hassall, after Chaucer and other sources.
• First performance at Covent Garden, London, on 3^rd December 1954.

Troilus is in love with Cressida, daughter of the High Priest Calkas, who advises surrender to the Greeks, following the Delphic oracle, and himself plans to desert to the Greeks. Pandarus, Cressida's uncle, succeeds in bringing her together with Troilus, but in the morning the Greek prince Diomede demands that Cressida be exchanged for the Trojan Antenor, taken prisoner by the Greeks. In the Greek camp Cressida hears nothing of Troilus, whose messages have been intercepted on the orders of Calkas. She is induced to give in to the urging of Diomede, but, when a truce has been arranged and ransom prepared for Cressida, Troilus arrives to find her newly married to the Greek. Troilus attacks Diomede and is killed by Calkas, who is sent back to the Trojans in chains, while Cressida kills herself.

Walton's romantic opera won some success in London at its first staging. Written in an idiom that might, at the time, have seemed dated, the work is uneven in quality. A concert suite derived from the score by Christopher Palmer in 1987 may be heard occasionally in the concert-hall.