Georgios Gemistos Plethon, commonly known as Gemistos Plethon, was a Greek scholar and one of the most renowned philosophers of the late Byzantine era. He was a chief pioneer of the revival of Greek scholarship in Western Europe. As revealed in his last literary work, the Nomoi or Book of Laws, which he circulated only among close friends, he rejected Christianity in favour of a return to the worship of the classical Hellenic gods, mixed with ancient wisdom based on Zoroaster and the Magi.

The Byzantine Greeks were the Greek-speaking Eastern Romans throughout Late Antiquity and the Middle Ages. They were the main inhabitants of the lands of the Byzantine Empire, of Constantinople and Asia Minor, the Greek islands, Cyprus, and portions of the southern Balkans, and formed large minorities, or pluralities, in the coastal urban centres of the Levant and northern Egypt. Throughout their history, the Byzantine Greeks self-identified as Romans, but are referred to as "Byzantine Greeks" in modern historiography. Latin speakers identified them simply as Greeks or with the term Romaei.