At the beginning of the thirteenth century the Russian princes measured themselves against one another along the rivers and in their feuds — the fragmentation was not a misfortune come from outside but an order of their own making: each fortified his own domain against his neighbor. And far to the south Baghdad, capital of the Abbasid Caliphate, rested serene in the sense of its own greatness: five centuries of caliphal rule, the House of Wisdom, the libraries, the fame of being the center of Islamic learning. Toward them both moved an idol built by the victor: the Mongol machine of total war, in which every man is a unit of the decimal structure — tens, hundreds, thousands, tumens. It is the same machine of account that was the idol of Ur, only turned not upon grain but upon war.
The storm came out of the steppe, where no one had thought to look for it. In 1237 the army of Batu, grandson of Genghis Khan, fell on the divided Russian lands, taking city after city — Ryazan, Vladimir, many more — burning and slaughtering those who tried to hold out alone. And in February 1258 the Mongols of Hulagu took Baghdad. The last caliph, al-Musta'sim, had loftily refused to submit while raising no army and readying no defenses; the city surrendered and was given over to sack. The books of the House of Wisdom were thrown into the Tigris, the caliph was put to death, and the six-hundred-year line of the Abbasids was severed in a matter of days. Two different worlds broke against one and the same machine — and both met it divided, each alone.
After the collapse came a long captivity. Over the Russian principalities the Mongol yoke lay for nearly two and a half centuries: tribute, charters of rule handed out at the khan's court, punitive raids for any disobedience. The Islamic world lost its heart — the center of learning and of caliphal authority was destroyed, and Mesopotamia and Iran passed for long years under the rule of the conquerors. Where yesterday men had thought themselves eternal, they now counted their dead and paid tribute to a foreign master.
And yet through the captivity a return slowly showed — not the restoration of the old, but a gathering around a new center of gravity. Rus began to take shape again around different centers and around the Church: the metropolitan see, once of Kyiv, moved to Vladimir and then to Moscow. That quiet removal of the spiritual capital would prove weightier than many a victory: it laid the ground for the future primacy of Moscow, around which, two centuries later, a liberated realm would gather. The captivity was not annulled by a miracle — it was outlived, by the patient gathering of what had survived, under the shelter of faith.