There had been a prophecy among the mystics of Damascus: that the toppling of the old Christian order and Islam’s assumption of its place as the hegemon of the age would come to pass within a hundred years of Mohammad’s death. This prophecy offered a further tantalizing detail: that this supreme victory would be achieved by a caliph who bore the name of one of the prophets of old. A generation before, the great warlord Caliph Muawiya had tried and failed to decapitate the faltering Roman Empire in his five-year siege of Constantinople from AD 678 to 682. Surely the Caliph Sulayman (the Arabic form of ‘Solomon’) was divinely ordained to succeed where his grandsire had failed?

The auspices appeared good; the odds, heavily in the Arabs’ favour. Sulayman’s brother, Prince Maslama, commanded an army and fleet of astonishing size, unrivalled in strength and resource. They ran roughshod over the empire’s dwindling possessions in Asia Minor (Anatolia), advancing almost unchallenged to the gates of Constantinople.

That was about as far as their luck held. Prophecy or no, Maslama’s massive army seemed pitted against the hand of God almost from the outset. The Byzantines’ diabolically effective weapon – known as Greek fire by their enemies and hydron pyr (‘liquid fire’) by themselves – wreaked havoc on the very day of the Arab fleet’s arrival. (As described.) The wind dropped, the huge war-ships in the rearguard of the fleet found themselves becalmed, and the Byzantine fire-ships coolly destroyed two dozen of them without suffering a single casualty.

The impenetrability of the walls of Constantinople, defending the landward side of the city, was well attested for over a millennium. First constructed during the reign of Emperor Theodosius II in the fourth century AD, they were the brainchild of an architect named Anthemius. The walls stood intact practically until the city’s final capitulation to the Ottoman Turks in 1453. True, Constantinople had been sacked before that, in 1204, although that was achieved through treachery. It took the invention of gunpowder – and a shady arms deal between an unlikely Hungarian and the Turks – to finally blow a breach through the massive stone defences. The rest, as they say, is history.