This is the first critical edition with English translation of the prose compilation Tristano panciatichiano, preserved in a unique manuscript in the Biblioteca Nazionale of Florence (MS Panc. 33); it is the first time the Italian text has been published in its entirety in any form. Assembled by the mid-fourteenth century, the manuscript is an original compilation in Italian based on several French models: the Queste del San Graal, Joseph d'Arimathie, the Mort Artu, and notably, the Roman de Tristan en prose. While the edition itself will be of great interest, the translation into English is a major opportunity for Arthurians and other medievalists, and furnishes important new evidence for the study of Arthurian material in Italy. Apparatus includes a finding list of Arthurian manuscripts produced, owned or read by Italians; a select bibliography; and an index of proper names found in the narrative.