Byzantine Aristotelian Commentary: Photius and Michael Psellos

Photius (c. 810/820–893), twice Patriarch of Constantinople (858–867 and again 877–886) amid the bitter ecclesiastical dispute known as the Photian Schism with Rome, was among the most learned laymen of the mid-Byzantine period before his rapid elevation through clerical ranks to the patriarchate. His most celebrated work, the Bibliotheca (also called the Myriobiblos, "ten thousand books"), is a vast compendium summarizing and critically assessing 279 separate works — many of them classical, patristic, and secular texts that would otherwise be entirely lost to us — that Photius reportedly read and had transcribed for his brother Tarasius before departing on a diplomatic mission, possibly to the Abbasid court at Baghdad, though the exact circumstances and dating of the embassy remain debated by modern historians.