On August 15, Maslama was at the city walls, laying siege to it with various engines of war; the navy arrived two weeks later, on September 1. After a few fruitless attempts to breach the walls, Maslama settled to reduce the city by blockade, much of which would depend on the navy.
A close reading of the sources reveals that two important factors saved the empire: Arab inexperience at sea warfare and Greek ingenuity. The Arab warships nearing the Bosporus were heavy-laden with equipment and, in general, cumbersome. To lure the ships, Leo, in another stratagem, had the ponderous chain that normally guarded the harbor cast aside. “But while they hesitated whether they should seize the opportunity . . . the ministers of destruction were at hand”: Leo had sent out his fleet, with the secret weapon of the day, “Greek fire” (an incendiary composition projected by means of siphons), which conflagrated the Muslim ships into “blazing wrecks”: “Some of them, still burning, smashed into the sea wall, while others sank in the deep, men and all.”
Soon after this pivotal defeat, the ambitious caliph Suleiman, who had meant to fulfill Mohammed’s prophecy by conquering Constantinople, died of “indigestion” (according to the chroniclers, by devouring two baskets of eggs and figs, followed by marrow and sugar for dessert). To make matters worse, the new caliph, Omar II, seemed, at least initially, not to be as attentive to the needs of Maslama’s army. Winter set in, and the Byzantines retired to their fortified city, leaving the elements to deal with the Muslim camp. “One of the cruelest winters that anyone could remember” arrived, and, “for one hundred days, snow covered the earth.”
Still, Maslama’s brother, the late caliph, had commanded him to “stay there [Constantinople] until you conquer it or I recall you.” Neither had happened; the latter option was no longer possible. All Maslama could do was wait and assure his emaciated, desperate men: “Soon! Soon supplies will be here!” In the meantime, roaming Turkic tribes, particularly the Bulgars, who had yet to embrace Islam, began harrying the Muslim camp.
By springtime, reinforcements finally came, by both land and sea. It was not enough; frost and famine had hit the massive army of Maslama hard, to the point that cannibalism was resorted to. The Greek chronicler Theophanes relates: “Some even say they put dead men and their own dung in pans, kneaded this, and ate it. A plague-like disease descended on them, and destroyed a countless throng.” The plausibility of the second sentence offers support for the improbable first one. An independent chronicler, Michael the Syrian, wrote: “The hunger oppressed them so much that they were eating the corpses of the dead, each other’s feces, and other filth.”
From the new caliph’s point of view, that such a massive force, years to mobilize, was already at the gates of Christendom, made it very difficult to simply give up. As caliph — successor to the warrior-prophet and his companions, who had subjugated much of the known world — he could not accept defeat so easily. While the army made do, a new navy, composed of two war expeditions, one from Alexandria, Egypt, the other from North Africa — nearly 800 ships total — made its way to Constantinople. Under cover of night, they managed to blockade the Bosporus, threatening to cut off all communications from the city.
Moreover, the Muslim commanders were warier of the Greek fire, and kept their distance. Aware of this, Maslama’s army, somewhat recovered owing to supplies and fresh conscriptions, was once again on the move, besieging the city with — considering the abominable trials to which they had recently been subjected — a feral fury. It seemed that the beginning of the end, though delayed, had finally arrived.
Delivery for Constantinople came from the least expected source: the Egyptian crew manning the Alexandrian ships, the Christian Copts. Because the vast majority of the caliphate’s fighting men, the mujahidin, were already engaging the enemy, the caliph had no choice but to rely on Christian dhimmi (second-class) conscripts for reinforcements. Much to the caliph’s chagrin, however, the Copts all fled at nighttime to Constantinople, and acclaimed the Christian emperor.
Theophanes writes that, as the Copts seized light boats and fled in desertion to the city, “the sea looked entirely made of wood.” Not only did the Muslim war galleys lose a good deal of manpower, but the Egyptians provided Leo with exact information concerning the Muslims’ ships and plans. Taking advantage of this, Leo once again released the fire-ships from the citadel. Considering the loss of manpower after the Copts’ desertion, the confrontation was more a rout than a battle.
It is worth noting that this little-known fact — that Copts abandoned the Muslim fleets in droves to join forces with the Christian emperor — indicates that, from the start, Christian life under Muslim rule was not as tolerable as later revisionist history (which claims that the Copts of Egypt welcomed the Muslims as “liberators” from the Byzantine yoke) makes it out to be.