The play was entered into the Stationers' Register on March 12, 1606, and published later that year, in two separate states: the Epistle in the second states that it is a corrected version of the first, by the author. An apparent allusion in IV,i, 310 to the bloody execution of Sir Everard Digby on Jan. 30, 1606, indicates that Marston revised the play after that date.
The play tells the story of Duke Hercules, who disguises himself as a flattering courtier, the Fawn, in order to infiltrate the court of Duke Gonzago and observe the behaviour of his son Tiberio, who has been sent to Gonzago as an ambassador. In the process, Hercules observes the lechery of Gonzago's courtiers, who are all embroiled in seedy sexual adventures, and the vanity and stupidity of Gonzago himself, who is a pompous old windbag. At the play's conclusion, Hercules holds a symbolic Court of Cupid, in which all the foolish courtiers are arrested for their crimes against love and good sense.
It is often assumed that Duke Gonzago was intended as an unflattering portrait of King James I, although it is not known whether the king took offence at this portrayal.
A parasitaster is one who pretends to be a parasite or sycophant. The term in Marston's original coinage, following the example of Ben Jonson's coinage of the term poetaster for an inept and pretentious versifier, in his play of the same name.