The revival of Greek in Italy, where Greek literature was practically unknown, is due in great measure to the arrival of Greek scholars, who were induced to come by promises of a salary and position, or who travelled thither on political or ecclesiastical missions. Of these the principal were Manuel Chruysoloras engaged at work in Florence from 1396, Cardinal Bessarion (1403?-72) who came westward for the Council of Florence and ended his days in Venice to which he bequeathed his library, Gemistos Plethon (1355-1450) the principal agent in the establishment of the Platonic academy at Florence, George of Trebizond, Theodore Gaza, Lascaris, Andronicus Callistus, and others who fled from Greece to escape the domination of the Turks. With the help of these men and their pupils a knowledge of Greek and of Greek literature was diffused through Italy, and in a short time throughout the Continent. Everywhere collections of Greek manuscripts began to be formed; agents were sent to the East to buy them wherever they could be discovered, and copyists and translators were busy at work in all the leading centres of Italy. The fall of Constantinople in 1453 tended to help the Greek revival in the West by the dispersion of both scholars and manuscripts through Italy, France, and Germany. Humanism owes its rapid development in Italy not indeed to the universities, for the universities, committed entirely to the Scholastic principles of education, were generally hostile, but rather to the exertions of wandering teachers and to the generous support of powerful patrons. In Rome it was the Popes who provided funds for the support of Humanist scholars, for the collection and copying of manuscripts, and for the erection of libraries where the great literary treasures of Greece and Rome might be available for the general public; in Florence it was the de' Medici, notably Cosmo (1429-64) and Lorenzo the Magnificent (1449-92), by whose exertions Florence became the greatest centre of literary activity in Europe; in Milan it was the Viscontis and the Sforzas; in Urbino Duke Federigo and his friends; and in Ferrara and Mantua the families of d'Este and Gonzaga. Academies took the place of universities. Of these the academy of Florence, supported by the de' Medici and patronised by the leading Greek and Italian scholars, was by far the most influential and most widely known. The academy of Rome, founded (1460) by Pomponius Laetus, was frankly Pagan in its tone and as such was suppressed by Paul II. It was revived, however, and patronised by Sixtus IV., Julius II., and Leo X. Similar institutions were to be found in most of the Italian States, notably at Venice and Naples. In nearly all these cities valuable manuscript libraries were being amassed, and were placed generously at the disposal of scholars.