It would be better to see the turban of the Turks reigning in the center of the City than the Latin miter.
Κρειττότερον ἐστὶν εἰδέναι ἐν μέσῃ τῇ Πόλει φακιόλιον βασιλεῦον Τούρκου, ἢ καλύπτραν Λατινικήν.
Original text (Ancient Greek)
Source, in full
Reported in Doukas, Historia Turco-Byzantina, ch. 37, sect. 10; Harry Magoulias, Decline and Fall of Byzantium to the Ottoman Turks (Detroit: Wayne State UP, 1975) p. 210. The attribution is probably wrong; see Kenneth M. Setton, The Papacy and the Levant, 1204–1571, Vol. 2: The Fifteenth Century (Philadelphia: The American Philosophical Society, 1978) pp. 104–105, esp. note 91
Notes from Wikiquote
Gibbon, Decline and Fall of the Roman Empire, vol. 6 (1782; ed. H. H. Milman, 1845) ch. 68: "The Latins were the most odious of heretics and infidels; and the first minister of the empire, the great duke, was heard to declare, that he had rather behold in Constantinople the turban of Mahomet, than the pope’s tiara or a cardinal’s hat."