The history of Constantinople, or more generally of the Eastern Roman empire, wears a peculiar interest to the children of Christendom; and for two separate reasons--_first_, as being the narrow isthmus or bridge which connects the two continents of ancient and modern history, and _that_ is a philosophic interest; but _secondly_, which in the very highest degree is a practical interest, as the record of our earthly salvation from Mahometanism. On two horns was Europe assaulted by the Moslems; first, last, and through the largest tract of time, on the horn of Constantinople; there the contest raged for more than eight hundred years, and by the time that the mighty bulwark fell (1453), Vienna and other cities upon or near the Danube had found leisure for growing up; so that, if one range of Alps had slowly been surmounted, another had now slowly reared and embattled itself against the westward progress of the Crescent. On the western horn, _in_ France, but _by_ Germans, once for all Charles Martel had arrested the progress of the fanatical Moslem almost in a single battle; certainly a single generation saw the whole danger dispersed, inasmuch as within that space the Saracens were effectually forced back into their original Spanish lair. This demonstrates pretty forcibly the difference of the Mahometan resources as applied to the western and the eastern struggle. To throw the whole weight of that difference, a difference in the result as between eight centuries and thirty years, upon the mere difference of energy in German and Byzantine forces, as though the first did, by a rapturous fervor, in a few revolutions of summer what the other had protracted through nearly a millennium, is a representation which defeats itself by its own extravagance. To prove too much is more dangerous than to prove too little. The fact is, that vast armies and mighty nations were continually disposable for the war upon the city of Constantine; nations had time to arise in juvenile vigor, to grow old and superannuated, to melt away, and totally to disappear, in that long struggle on the Hellespont and Propontis. It was a struggle which might often intermit and slumber; armistices there might be, truces, or unproclaimed suspensions of war out of mutual exhaustion, but peace there could _not_ be, because any resting from the duty of hatred towards those who reciprocally seemed to lay the foundations of their creed in a dishonoring of God, was impossible to aspiring human nature. Malice and mutual hatred, we repeat, became a duty in those circumstances. Why had they _begun_ to fight? Personal feuds there had been none between the parties. For the early caliphs did not conquer Syria and other vast provinces of the Roman empire, because they had a quarrel with the Caesars who represented Christendom; but, on the contrary, they had a quarrel with the Caesars because they had conquered Syria, or, at the most, the conquest and the feud (if not always lying