While the North Asian invaders retreated into the mountains to escape the summer heat, the cry of jehad rose up in the mosques and circulated through the towns and cities. The Turks, Persians, Afghans, and Arabs responded to the call and gathered around the leaders of their own races. They lacked unity of command and each leader was motivated by his own ambition—but with more than a million men, excellent horses, and the best arms and armor they far outnumbered the 150,000 Mongols.
 Jehad (exertion) in the path of God (from the Koran, chapter IX verse 29). Read in the context of the times this verse was meant to protect the early Muslim Arabs from their neighbors—it later became a tool for the Islamic conquests. Under the Turks this verse became the justification for all the massacres and plundering in Europe and India. Today it is used to indoctrinate Islamist extremists in madrassas and terrorist camps.
The situation was critical for Chingiz Khan because some of his subordinate allies, like the Uighurs, had just then taken permission to return to their own homes. His best generals, Chepe and Subotai, were exploring new lands in the west—while Muqali was administering faraway China. Some other generals like Tilik Noyon had died in the recent campaigning and the total strength of the Mongol army had been thinned. So the reports of the millions scattered in different cities arming and raging for jehad alarmed Chingiz—but with stern determination he planned and executed the bloodiest campaign of his career.
Until now the war had been fought on the standards of those times where the ruling class and the soldiery were eliminated if they resisted but the majority of the population was left alone. However when that same population took to arms and called for the murder of all unbelievers these standards had to be changed. And with this in mind Chingiz ordered his sons and generals, “I forbid you to show mercy to my enemies without an explicit order from me. Firmness alone keeps such spirits dutiful. An enemy conquered is not subdued, and will always hate his new master.”
The Mongol threw whatever he had at the cities of Islam before these millions could be gathered and led by Jelal-ud-din. His soldiers, in obedience of the explicit orders, massacred every living soul inhabiting those cities. When they learned that people were trying to save themselves by falling on the heaps of the slain and playing dead, the Mongol generals ordered their soldiers to cut-off the heads of all enemies. Those who saved themselves by hiding could not escape—at one place the retreating Mongols sent back groups of soldiers to hunt out and kill these persons. In another city they forced the muezzin of a mosque to cry out the loud call to prayer—the Muslims came out of their hiding places, in the belief that the hated Mongols had left, and were massacred.
The cities too were burned and dismantled—the walls were razed down and even the foundations were dug up and ploughed over with soil so that no trace of the habitation was left! And all this while select Mongol units chased and fought Jelal-ud-din all across his father’s former domain, giving him no chance to gather an effective army. When the summer heat returned the Mongols withdrew once again into the cool mountain ranges.
This time they set up camp in the Afghan mountains and did not indulge in a hunt. It had been a successful but intense campaign and there was plenty of rest and recuperation needed. News from west came that General Chepe had died while leading his army back to Chingiz. The Khan’s eldest son Juchi had been sent to camp in the wild lands around the Aral Sea because of his failure to capture Jelal-ud-din at Urgench. Tuli the youngest had also given cause for Chingiz to be angry—after storming many cities and slaughtering the inhabitants Tuli had taken mercy on the people of Herat, had forbidden the slaughter and had placed a Mongol to govern over them.
Chingiz Khan’s anger was justified when, in the coming autumn, the jehadis of Heart rebelled and killed the Mongol governor and his men. Tuli was sent to redeem his earlier mistake while Chingiz took 60,000 men to finally hunt down the elusive Jelal-ud-din in person.
Up to this time the lands in the east, on the border with India and among the Afghan hills, had not been affected by the Mongol conquest. Hence Jelal-ud-din had raised a fresh Turk army from the garrisons here and was marching north—to the important city of Bamiyan that held a large garrison of its own along with some treasure. Chingiz reached that place before the Muslims and sent a part of his army with a Mongol general to deter the Turk prince. With the rest of his army the Khan besieged Bamiyan.
The defenders of Bamiyan had prepared for the coming contest by destroying all the grass and crops of the countryside—they had even gone to the extent of removing the thousands of boulders and stones that could be used by the Mongol siege engines! The only option for Chingiz was to raise wooden towers and shoot flaming arrows into the crowded city and then scale the walls. The Mongols redoubled their efforts at Bamiyan—their middle-aged emperor got off his horse and ignited the spirit of his men by running forward at the very head of one of the storming units into the doomed city.
Chingiz left the destroyed city of Bamiyan to collect his scattered divisions. When Jelal-ud-din learnt that Bamiyan was gone and Chingiz had pulled together his army he fled towards India—these events will be described later.
Across the Turk empire cities had been pillaged and burnt, hundreds of thousands had been killed, and hundreds of thousands had been dragged away from their homes in slavery. Truly a horrifying story—but this same story had been told much earlier when the banners of Islam had first entered these lands. And in the same way the Turks had created such bloody scenes in attacking the cities of India. But the Muslim invasions went further in forcing the population to convert to their religion—and in this respect the Mongols differed greatly from them.
After the horrors of an Islamic invasion the conquered population was persuaded to convert to Islam. Those that refused would be forced to live under repressive laws, forbidden to ride horses or bear arms, forced to pay a capitation tax, and forbidden from building new places of worship. Over time, it was calculated, such pressures would force the people to finally embrace Islam.
After the horrors of a Mongol invasion the population was declared free to follow their ancestral faith as long as they obeyed the Mongol laws. The conquered peoples, Chins, Turks, Persians, were brought into the administration and even into the army. The Mongols kept their own traditions but allowed the Buddhists, Muslims, and Christians to debate each other and to propagate their faiths—but without the power of the state to help them in their mission. Much later the Mongol Empire broke into several mini-empires ruled by the various descendants of Chingiz—these rulers, having lost touch with their ancestral land of the Gobi, eventually converted to the faith of their subject peoples.
(on the left Chingiz is portrayed with Sinic features while on the right he has a distinct Turkic physiognomy. These paintings were done long after the death of Chingiz by his subjects in China and Central Asia.)
At the time of the Mongol invasion of Central Asia and Iran the peoples to their west were engaged in bloody religious wars. The crusades had pitted Europeans against Arabs, Armenians against Turks, Christians against Jews, and Muslims against Christians in wars that seemed to serve no purpose. The Mongols under Ogdai, the son of Chingiz, and later under Mangu, his grandson, defeated the Seljuk Turks, the Christians of Antioch, and the Mamluk Turks. For the brief duration of Mongol rule over West Asia, Christian, Muslim, and Jew could freely perform the duties of their religions and visit the holy places of their prophets unhindered.
It should also be remembered that there were many Muslims serving under Chingiz like the Naiman Turks, the Uighur Turks, the Muslims of Kara-Khitai, and many Turkomans. During the call for jehad these Muslims remained loyal to Chingiz and fought against their co-religionists without the least fear or apprehension. Had they joined the jehadis, the remaining army of Chingiz would have suffered greatly in trying to defeat the Muslims—but as long as they had religious freedom these Naimans, Uighurs, and Turkomans remained true to their salt and fought for Chingiz. For them the law of the Mongol Khan was above the law of the Prophet in the political sphere.
And after the fighting ceased the conquered Muslims became devoted to these same Mongol laws and followed them as religiously as they did the laws of the Koran. As late as in the 16th century the Turk prince Babur remarked in his memoirs, “My forefathers had always observed the rules of Chingiz Khan strictly…Now those rules certainly had no divine authority, so that a man had to obey them; still they were good to follow by those who inherited them. Every man who had such good regulations should follow them.”