The introduction of Greek philosophy and science into the culture of the Latin West in the Middle Ages was an event that transformed the intellectual life of Western Europe. It consisted of the discovery of many original works, such as those written by Aristotle in the classical period. Greek manuscripts had been maintained in the Greek-speaking world in Constantinople, the Near East and Egypt. Interest in Greek texts and their availability was scarce in the Latin West until traffic increased to the East, particularly the Byzantine Empire, during the time of the Crusades and the Latin rule of Constantinople following the sack of the Byzantine capital in 1204 during the Fourth Crusade. Finally, the Fall of Constantinople in 1453 to the Ottoman Empire caused many Byzantine Greek scholars to flee to Western Europe bringing with them manuscripts of classical works in the original Greek, thus fueling the Renaissance.
As knowledge of Greek declined in the west with the fall of the Western Roman Empire, so did knowledge of the Greek texts, many of which had remained without a Latin translation. The fragile nature of papyrus, as a writing medium, meant that older texts not copied onto expensive parchment would eventually crumble and be lost.
After the Fourth Crusade (1202-4) and the Sack of Constantinople (1204), scholars such as William of Moerbeke gained access to the original Greek texts of scientists and philosophers, including Aristotle, Archimedes, Hero of Alexandria and Proclus, that had been preserved in the Byzantine (Eastern Roman) Empire, and translated them directly into Latin.