Also known as Sacchi. Humanist; born in 1421 in Piadena, Italy; died in 1481 in Rome, Italy. Deprived of his membership in the College of Abbreviators by Pope Paul II he wrote a scathing and false account of his character in his Vitae Pontificum (Lives of the Popes), which influenced historical opinion for centuries; this work is the first systematic handbook of papal history. In this appears the legend of the excommunication of Halley's comet (1456), in which he mistakenly mentions the Bull of Pope Callistus III as the outcome of the comet.