The siege and conquest of Constantinople, by the Turks, is, perhaps, the only event in history, worthy to be compared with that of Bagdad, by the Mongols; and the fall of the long-sinking Byzantine empire, may be placed by the side of that of the khalifat. The conquest of other cities, on whose sieges history has dwelt with astonishment and admiration, or with pity and terror, is less mighty in its consequences, because, under their ruins, no throne of universal sway has been buried. This interest is wanting, in the most obstinate and glorious sieges of ancient and modern history, however remarkable by the great names of the assailants, or the consummate skill with which they may have been prosecuted, or the patient courage with which they have been defended. Tyre and Saguntum, illustrious in their besiegers, Alexander and Hannibal; Syracuse, which has immortalized the names of Marcellus and Archimedes; Rhodes, twice attacked by Demetrius Poliorcetes, and defended against the Turks, by Villiers de l’Isle Adam; Candia, and Saragossa; have all earned unfading glory, by the lion courage of their inhabitants and defenders; but, although these cities fought for the highest of earthly objects—their country’s freedom, still their fall did not draw down with it the seat of the ancient dominion over half the world. The history of the conquest of other celebrated cities, the seat of universal monarchy, such as Babylon and Persepolis, under whose ruin were buried the Assyrian and Persian monarchies, is wrapt in the distance of thousands of years, and impenetrable obscurity. The destruction of Jerusalem eclipses in the brightness of its lustre that of all those cities; not, however, on account of the importance of its power, or of its siege, for that by Khosroes was not less remarkable than that by Titus; but because the latter was described by Tacitus. If Gibbon had had access to the sources which are at our command, the conquest of Bagdad would not have shone with less splendour, in his immortal work, than that of Constantinople, nor would it have been so briefly treated. What we want of his power of expression, must be supplied by the richness of the material.