<P> Some of the first humanists were great collectors of antique manuscripts, including Petrarch, Giovanni Boccaccio, Coluccio Salutati, and Poggio Bracciolini . Of the four, Petrarch was dubbed the "Father of Humanism" because of his devotion or loyalty to Greek and Roman scrolls . Many worked for the Catholic Church and were in holy orders, like Petrarch, while others were lawyers and chancellors of Italian cities, and thus had access to book copying workshops, such as Petrarch's disciple Salutati, the Chancellor of Florence . </P> <P> In Italy, the humanist educational program won rapid acceptance and, by the mid-15th century, many of the upper classes had received humanist educations, possibly in addition to traditional scholasticist ones . Some of the highest officials of the Catholic Church were humanists with the resources to amass important libraries . Such was Cardinal Basilios Bessarion, a convert to the Catholic Church from Greek Orthodoxy, who was considered for the papacy, and was one of the most learned scholars of his time . There were several 15th - century and early 16th - century humanist Popes one of whom, Aeneas Silvius Piccolomini (Pope Pius II), was a prolific author and wrote a treatise on The Education of Boys . These subjects came to be known as the humanities, and the movement which they inspired is shown as humanism . </P> <P> The migration waves of Byzantine Greek scholars and émigrés in the period following the Crusader sacking of Constantinople and the end of the Byzantine Empire in 1453 greatly assisted the revival of Greek and Roman literature and science via their greater familiarity with ancient languages and works . They included Gemistus Pletho, George of Trebizond, Theodorus Gaza, and John Argyropoulos . </P> <P> Italian humanism spread northward to France, Germany, the Low Countries, and England with the adoption of large - scale printing after the end of the era of incunabula (or books printed prior to 1501), and it became associated with the Protestant Reformation . In France, pre-eminent humanist Guillaume Budé (1467--1540) applied the philological methods of Italian humanism to the study of antique coinage and to legal history, composing a detailed commentary on Justinian's Code . Budé was a royal absolutist (and not a republican like the early Italian umanisti) who was active in civic life, serving as a diplomat for François I and helping to found the Collège des Lecteurs Royaux (later the Collège de France). Meanwhile, Marguerite de Navarre, the sister of François I, was a poet, novelist, and religious mystic who gathered around her and protected a circle of vernacular poets and writers, including Clément Marot, Pierre de Ronsard, and François Rabelais . </P>

How did humanism help define the italian renaissance