had to reckon with Mecca. Eight years of ferocious wars with the Quraysh bloodied the establishment of Islam. At the darkest hour, his face smashed up and smeared with blood, Muhammad was dragged from the battlefield by one of his warriors, and only the rumor that he was dead saved the remnants of his army. The ummah’s morale was crushed, and it was about then that Muhammad made his fighters a promise that would echo through history. The slain in battle, it was revealed to him, would be swept up to the highest level of Paradise: “They shall be lodged in peace together, amid gardens and fountains, arrayed in rich silks and fine brocade. . . . We shall wed them to dark-eyed houris.”
The Muslims—“those who submit”—clung on, and clinging on against the odds itself seemed a sign of divine favor. The decisive moment was not a battlefield victory but a spectacular public-relations coup. In the year 628 Muhammad unexpectedly appeared before Mecca with a thousand unarmed pilgrims and asserted his lawful right as an Arab to worship at the Kaaba. As he solemnly performed the rituals, while the Quraysh stood sullenly by, the rulers of Mecca suddenly looked more foolish than invincible, and opposition began to crumble. In 630 Muhammad returned with massed ranks of followers. He once again circled the sanctuary seven times, intoning “Allahu akbar!”—“God is great!”—then climbed inside, carried out the idols, and smashed them to pieces on the ground.
By the time he died, two years later, Muhammad had pulled off a feat that no other leader in history had even envisaged: he had founded a flourishing new faith and an expanding new state, the one inseparable from the other. In little more than a year the armies of Islam crushed the Arab tribes that held out against the new order, and for the first time in history the Arabian Peninsula was united under one ruler and one faith. Driven by religious zeal, a newfound common purpose, and the happy alternatives of vast spoils in life or eternal bliss in death, God’s newly chosen people looked outward.
What they saw were two superpowers that had been doing their utmost to obliterate each other from the face of the earth.
For more than a millennium, East and West had faced off across the River Euphrates in Mesopotamia, the fertile land long known as the cradle of civilization and today home to Iraq. On the eastern side was the illustrious Persian Empire, the guardian of an ancient, refined culture and of the world’s first revealed religion, the monotheistic faith of the visionary priest Zarathuster—a faith known after his Latinized name, Zoroaster, as Zoroastrianism—that told of creation, resurrection, salvation, apocalypse, heaven and hell, and a savior born to a young virgin centuries before the birth of Christ. Led by their great shahanshahs —“kings of kings”—the Persians had been the inveterate foes of the Greeks until Alexander the Great had smashed their armies. When Persia’s power revived, it had simply transferred its hostility to the Greeks’ successors, the Romans. The ancient struggle was the formative East-West clash, and in 610, just as Muhammad was receiving his first revelations, it had finally exploded into total war.
As waves of barbarians ran riot around western Europe, the emperor Constantine had built a new Rome on Europe’s eastern brink. Glittering Constantinople looked out across the Bosporus, a strategic sliver of water that leads from the Black Sea toward the Mediterranean, at Asia. Ensconced behind the city’s impregnable walls, Constantine’s successors watched helplessly as the Persians swept across their rich eastern provinces and headed toward holy Jerusalem. Long ago the Romans had razed Jewish Jerusalem to the ground, and a new Christian city had risen over the sites identified with Jesus’s passion; Constantine, the first Christian emperor, had himself built the Church of the Holy Sepulcher over the purported places of