Italian romance writer Rustichello da Pisa (a.k.a. Rusticiano, fl. late 13th century) translated or compiled what seem to be the earliest Arthurian romances written by an Italian. However he is best known for co-writing Marco Polo's autobiography, The Travels of Marco Polo, while both were imprisoned in Genoa.
While he was Italian, he seems to have written in French, with his first known work seemingly based on an account of the legends associated with King Arthur based on a copy of a work in Latin that England's Edward I left in Italy on his way to particip[ate in the the Eighth Crusade (1270 – 1274). The Roman de Roi Artus (a.k.a. the Compilation) the first known romance dealing with the Arthurian legend by an Italian author. The Arthurian material recounts in the Tristan's chivalric exploits alongside those of his father Meliadus, and other knights including Lancelot and Guiron le Courtois.
Rustichello cites the works of Luces de Gast, and also Robert and Helie de Boron as sources for his work, which also includes a history of the Round Table and an account of Arthur's Saracen knight Palamedes. His work remained popular for hundreds of years, and influenced later French, Spanish, Italian, and Greek writers.
He may have travelled through France and England before he was captured by the Genoese. possibly at the Battle of Meloria i(1284). If so, he was still there to take down Marco Polo's account of his travels in Central Asia and China when the Venetian was held for ransom after a clash between Genoa and Venice around 1298.
The details he dictated to Rustichello subsequently appeared under a number of titles, most widely as The Travels of Marco Polo. It is quite possible that without Rustichello The Travels would never have been written.
Sources:
Patricia M. Gathercole, Illuminations on the Manuscripts of Rusticien de Pise (Rustichello da Pisa),
The Oxford Dictionary of the Middle Ages