FWIW: The Encyclopedia Brittanica's entry on Emperor Manuel II Palaeologus of Byzantium, cited last week by Pope Benedict as an authority on the evils of Islam. He doesn't appear to have a particularly important leader; the Byzantine Empire was on its last legs, kept alive only by internal divisions in the Ottoman Empire, and would ultimately disappear from the world stage during the reign of his son. The writings cited by the Pope were likely written for the purpose of fomenting anti-Muslim feelings in the West at the end of the Fourteenth Century, when Manuel's empire was besieged, but he also played his cards well for a time with certain factions among the Turks, and remained in power for well over three decades as a vassal. Why the pope was inspired to cite him as an authority on any theological points staggers the imagination.