More than 800 years after its invention in medieval France, the sestina survives and thrives in English. A fixed 39-line poetic form with of six stanzas of six lines each, followed by a three- line stanza known as an envoi, tornada, or tercet, the sestina is the one form of poetry that poets from all camps agree can exist in a free verse world. Formalists and avant-gardes love sestinas for their ornate, maddeningly complicated rules of word repetition. For The Incredible Sestinas Anthology, editor Daniel Nester has gathered more than 100 writes from John Ashbery to David Lehman to Matt Madden and Patricia Smith to show the sestina in its many incarnations: prose and comic sestinas, collaborative and double sestinas, from masters of the form to brilliant one-off attempts, all to show its evolution and the possibilities of this dynamic form.