Libel is a verse genre primarily of the Renaissance, descended from the tradition of invective in classical Greek and Roman poetry. Libel is usually expressly political, and balder and coarser than satire. Libels were generally not published but circulated among friends and political partisans in manuscript.
In ancient Greece, invective verse generally existed in the form of epigrams written, almost always anonymously, against public figures. In Latin, the genre grew in prestige and boldness, as major authors including Juvenal and Catullus wrote extended invectives without the cushion of anonymity. One of Catullus's fiercer examples, expunged from most post-classical collections of his work until the 20th century, is Catullus 16, written against two critics:
Pedicabo ego vos et irrumabo,
I'll sodomize and face-fuck you,
In 17th-century manuscript culture, in which verses were copied out and distributed among (usually aristocratic) social groups, libel achieved a new standing. At the same time, the growing power of Parliament allowed the genre a new currency, since prominent members of Parliament could be attacked with greater freedom than could royalty. Libels frequently substituted humor and scatological inventiveness for poetic quality, as in the case of this well-known and much-circulated example, "The Censure of the Parliament Fart," which was in response to an audible emission by MP Henry Ludlow in 1607:
However, libels were also written by much better poets with considerably more technical achievement. John Wilmot, 2nd Earl of Rochester was one of the more accomplished practitioners; Rochester is still held in high esteem by literary critics.