The Duke's Mistress is a Caroline era stage play, a tragicomedy written by James Shirley and first published in 1638.
The Duke's Mistress was licensed for performance by Sir Henry Herbert, the Master of the Revels, on 18 January 1636, and was acted by Queen Henrietta's Men at the Cockpit Theatre.
[1] The play shares some clear similarities with contemporaneous works like The Queen and Concubine by Richard Brome and A Wife for a Month by John Fletcher.
[2] Shirley's use of the idea of men who are attracted to ugly women has provoked commentary on the psychological and other aspects of such a fixation.
In the main plot, Dionisio Farnese, the Duke of Parma, tries to dismiss his faithful wife Euphemia and win Ardelia as his mistress.
The play opens with a celebration in Ardelia's favor – which is interrupted by Duchess Euphemia, who melodramatically begs her husband to put her to death now that she has lost his affection.
Pallante lied about the Duke's death, but told the truth about Farnese's repentance – for that is what caused the assassin to spare his victim's life.