||After the Ottoman invasion of the territory of the Byzantine Empire and the fall of Constantinople in 1453, many excellent scholars migrated to Europe. Their most important destinations became the Italian cities (Florence, Venice, Ferrara, etc.). During the heyday period of these cities, Humanism, the renaissance of ancient culture, and the cult of antiquity played an important role, and the Italian Renaissance spread to other parts of Europe. After centuries of oblivion in the Latin Middle Ages, the impact of Greek language and literature on the knowledge of humanists was indisputable. Following the increasing interest in Greek antiquity during the Quattrocento, the leading humanists of Italy and France became familiar with ancient Greek culture, while the Byzantine scholars who migrated to Europe studied Latin and the vernacular languages. But this interaction was gradually decreasing as classical Greek works were beginning to be translated into Latin. Additionally, these translations made Greek literary, historical, and philosophical works accessible even to those who had a very limited or no knowledge of Greek. In this paper, I would like to illustrate the complexity of this phenomenon using the example provided by Bartolomeo Fonzio, one of the well-known humanists of the second half of the 15th century. Through his case, I would like to present how the knowledge of Greek became indispensable during the Quattrocento. Also, I intend to prove that earlier views about Fonzio’s Greek need reconsideration.