Michael Psellos or Psellus was a Byzantine Greek monk, savant, writer, philosopher, imperial courtier, historian and music theorist. He was born in 1017 or 1018, and is believed to have died in 1078, although it has also been maintained that he remained alive until 1096. He served as a high ranking courtier and advisor to several Byzantine emperors and was instrumental in the re-positioning of power of those emperors. Psellos has made lasting contributions to Byzantine culture by advocating for the revival of Byzantine classical studies, which would later influence the Italian Renaissance, as well as by interpreting Homeric literature and Platonic philosophy as precursors and integral components of Christian doctrine. His texts combined theology, philosophy, and psychology. Among his most famous works are his Commentary on Plato’s Teachings on the Origin of the Soul, and the Chronographia, a series of biographies from emperor Basil II to Nikephoros III, which serves as a valuable source on the history of the 11th century Byzantine Empire.

Medieval Greek is the stage of the Greek language between the end of classical antiquity in the 5th–6th centuries and the end of the Middle Ages, conventionally dated to the Ottoman conquest of Constantinople in 1453.