[1] The play belongs to the final phase of Shirley's career as a London playwright, when he was no longer serving as the house dramatist of Queen Henrietta's Men.
Nineteenth-century and twentieth-century critics, including Edmund Gosse and Fredson Bowers, considered it among his finest works.
Bowers called Shirley's play a "coherent Kydian revenge tragedy, polished and simplified in his best manner.
"[4] The play was revived early in the Restoration period, with an opening night at the Theatre Royal in Vere Street on 23 July 1662.
[5] Two lords praise the qualities of the Duchess, who has just finished mourning for her lost husband; they voice their disapproval of The Cardinal's plans to marry her to his nephew, Columbo.
The Secretary arrives and brings news that the men are preparing for war and Columbo has been chosen as general.
Hernando, Alphonso, and Columbo are holding a war council to discuss the lack of preparedness and training among the army.
The secretary persuades some servants to present a play for the King and court, in celebration of the Duchess's marriage.
Columbo takes responsibility and produces the letter the Duchess wrote asking him to release her, which he says is proof of her attempt to discredit his name.
Hernando arrives to entreat the Duchess to devise some revenge for Alvarez's murder, proposing himself to kill Columbo, then the Cardinal.
Hernando sets up a duel between himself and Columbo, ostensibly to avenge his honor at being dismissed from the field during battle.
Celinda brings the Cardinal a document that makes him happy and able to plan a dastardly revenge for the Duchess.
He promises to "rifle first her darling chastity, / 'Twill be after time enough to poison her" and seek his revenge on Hernando when she is dead.
The Cardinal confesses his many sins and asks for the King's pardon, and then reveals that he poisoned the Duchess at dinner and she is already dying.