The Mongol invasions of the Islamic lands represented a watershed in the history of the Islamic world. It was the first time, since the establishment of the Khalifate more than six hundred years earlier, that a significant part of the Islamic world had been subjected to the domination of a non Muslim power.

It was in the year 615 A.H. that the storm burst. At the time of the Mongol eruption, in spite of the frequent wars of which the plains of Transoxania , khorasan,  and Fares had been the theater, these countries were most flourishing; the people were prosperous: literature, arts, and crafts of every kind were cultivated, encouraged and patronized; the cities were populous, and embellished with fine public and private structures, the outcome of centuries of prosperity and Islamic civilization.

Herat and Balkh each had a population of a million; in Bokhara (1) and Samarqand it far exceeded that number. The forces of  Khwarism Shah were simply swept away as by a torrent. Leaving out the minor cities and towns, it is enough to describe what happened in the principal centers of civilization and trade. Khojand was razed to the ground, Bokhara and its inhabitants passed under the sword. Bokhara was reduced to ashes. Ibn el-Athir account of the sack of this seat of learning depicts in vivid terms the terrible cruelties inflicted by the savages upon the helpless inhabitants; Advancing in 1219 A.D.  along the beautiful valley of the Soghd, " The Scourge of God " arrived at Samarqand, which was not only the capital of Transoxiana, but also one of the greatest entrepots of commerce in the world. The city was three miles in circumference, and surrounded by a wall pierced by twelve iron gates, with castles at intervals. Its garrison consisted of 110,000 men, of whom 60,000 were Turkomans and Kankalis and 50,000 Tajiks or Persians. The three armies that had overrun Northern Transoxiana now converged upon the doomed city, and an immense body of men invested it. The Turkish mercenaries, who thought they would be treated as compatriots by the Mongols, deserted with their families and goods, but were immediately put to death. Upon this the Imams and the notables issued and offered to surrender. In spite of their submission the city was sacked, and an immense number of people were killed; 30,000 artisans were assigned by Chengiz as slaves to his several sons; an equal number were set aside for military works, transport service, etc. Of its million inhabitants, 50,000 alone remained to tell the fate of the ruined city. 

Warned by the fate of Bokhara and Samarqand, the citizens of Balkh sent the Mongol leader presents and offered their submission to him, but he was afraid to leave it behind him. On pretense of counting its inhabitants, he enticed them out of the city, and then slaughtered them; the city itself was burned to the ground. In May 1220 A.D. the savage horde captured Urganj (old Khiva), after a desperate fight, which was followed by a general massacre. The Mongols then destroyed the city by opening the dykes of the Oxus.

At Nessa they made a hecatomb of over 70,000 people; men, women, and children who were told to lie down side by side, where they were then tied by cords and killed by arrows. Nishapur, the capital of the Tahirides, and the Persian Seljukides, was destroyed in April 1221 A.D. It was razed to the ground, and its site was sown with barley; only 400 artisans escaped, and they were transported to the north. 

According to Mirkhond 1,747,000 men lost their lives in the massacre at Nishapur and the surrounding districts. In Herat, Massacre and its environs, they killed, burnt, and destroyed for  a week, and it is said that 1,600,000 people were killed, the place was entirely depopulated, and the neighborhood turned into a desert. Rai, Dinawar, and Hamadan were sacked, and a large portion of the population put to the sword. The Mongols then marched upon Iraq, which belonged to the Khalif, but were beaten back by el-Mustansir's troops.

In Transoxiana and Khorasan the civilization of centuries was completely destroyed, and the people were plunged into a depth of barbarism in which the remembrance of their former greatness and their whole future were alike engulfed. The great highroads of Central Asia, by which the products of China and India were conveyed to Western Asia, and to Europe, were deserted, the tracts well known for their fertility lay barren neglected, and finally destroyed; the arts and manufactures, so celebrated throughout Islam, decayed for ever. The towns were in ruins, the peasants either murdered or compulsorily enrolled in the Mongolian army, and the artisans sent off by thousands to the farthest east to adorn and beautify the home of the barbarian conqueror. 

The Mongol eruption put an end to the intellectual life of Central Asia, for although Persia and the western lands of Islam  gradually recovered from their misfortunes, Bokhara and Samarqand never regained their former mental activity, and their intellectual labors were henceforth entirely devoted to casuistry and mysticism. After converting Central Asia and Persia into a desert Chengiz retreated to the steppes, where he subsequently died. 

Meanwhile the Khalif el-Mustansir also died in 1242 A.D.,  his death came at the most critical period in the destiny of Islamic civilization. He was succeeded by his son Abou Ahmad Abdullah, who received the title of al-Musta3sim billah.

Unlike his name the new khalif was weak, vacillating, and fond of pleasure, his reign was one of continuous record of disturbance and disorder at home and disaster abroad, culminating in his destruction and that of his dynasty. The quarrels of the Hanafiys with the Hanbaliys, who were the source of constant trouble in Baghdad;  the  bickering of the Sunniys with the Shi`a who inhabited the western suburb of el-karkh and most of all the quarrels of the rabble and the bud mashes with the moneyed classes and the aristocracy, made Musta3sim's life a burden.  Further he accentuated these disorders by disbanding his father's army, and directing them to take to trade and husbandry. 

A riot between the Shi`as and the Sunnis led him to give an order to his son, Abou Bakr, and his secretary to demolish the suburb of el-Karkh, and to expel them. Mu'ayyid ud-diyn Muhammad bin el-Qoumiy,  the vizier, who was a Shi`i, was grieved at this, and is said to have invited the Mongols to come to Baghdad.

The Arab historians, Ibn Khaldoun, Abu'l Fida', el-Maqrizi, and el-Suyouty all describe the Vizier as a traitor;  under one of the later Ilkhanid Mongols, Rashid ud-diyn alone describes him as a faithful servant anxious to save the dynasty from the impending ruin, but helpless under the stupidity and vacillation of the nerveless Khalif.  However it be, Hulaku, who was acting in Persia as the lieutenant general of his brother Mangu Khan, after exterminating the Assassins and destroying their castles, marched towards Tabriz, whence he sent some envoys to el-Khalifa el-Musta3sim with the following message:

The khalif, without an army, with half-hearted councilors and a city torn by intestine dissension, instead of bowing to the storm, returned a haughty reply, and the rabble insulted the departing Mongols. This threw the heathen savage into a rage. Hulaku advanced on the capital of el-Abbasid with a force which could beleaguer the city all round.

The khalif's troops attempted to make some stand against the invaders before they arrived in the neighborhood of Baghdad. But divided counsels led on one occasion to a disastrous repulse, and on another to a fruitless loss of life. The Mongols now resolved on blockading Baghdad.

He repaired to the Mongol camp, attended  by his brother and his two sons, together with a suite of nearly three thousand persons Qadis, Shaikhs, Imams, and other notables; only the khalif and the three princes, his brother and two sons, together with three of the suite, were admitted to an audience. 

The savage chief concealed the perfidy of his designs under the mask of smooth words and a most friendly reception. He requested the khalif to send word into the city that the armed inhabitants should throw away their weapons, and assemble before the gates, in order that a general census might be taken. 

At the order of the khalif the city poured out its unarmed defenders, who were immediately secured. The next day 9th of Safar 658 A.H./ 1260 A.D., at sunrise, Hulaku issued commands for the sack of the devoted city and the massacre of all the people of Baghdad.

The women and children who came out of their houses with the Qur'an in their hands, imploring quarter, were trampled to death and mercilessly massacred. Delicately nurtured ladies who had never braved  the sight of crowds were dragged into the open streets and subjected to the grossest brutalities; the artistic and literary treasures, collected with such labor and industry  by sovereign after sovereign, were destroyed in the course of a few hours. For three days the streets ran with blood, and the water of the Tigris was dyed red for miles along its course. The horrors of rapine, slaughter, and outraged  humanity lasted for six weeks. The palaces, mosques, and mausoleums were destroyed by fire or leveled to the earth for their golden domes. The patients in the hospitals, and the students and professors in the colleges,  were put to the sword. In the mausoleums the mortal remains of the shaikhs and pious Imams, and in the academies the immortal works of great and learned men,  were consumed to ashes; books were thrown into the fire, or, where the Tigris was near, buried in its waters.

The accumulated treasures of five centuries were thus for ever lost to humanity, and the flower of the nation. Death of was completely destroyed. After the carnage had lasted four days, el-Musta3sim was beaten to death, together with his sons and the principal members of his, family. A  few obscure members of the house of el-Abbas alone, escaped the destruction. Baghdad, the abode of learning the seat of culture, the eye and center of the Islamic world world, was ruined for ever.

The population before the sack was over two millions; according to Ibn Khaldun, one million six hundred thousand people perished in the slaughter of six weeks. With the destruction of Baghdad the gloom of night settled on Western Asia. The Muslim authors speak in harrowing strains of the havoc and ruin caused by the myriads of savages and heathens who, swept over the Islamic world in the middle of the thirteen century, and none but a fanatic can help shedding tear over, the fearful loss of human life and the destruction of intellectual treasure, or the carnage and atrocities committed by the Mongols. 

Jouwani, the author of the Jahan Kusha, who was, in the service of Ghengiz about this time,  says, "the revolution which has overwhelmed the world, has destroyed learning and the learned, especially in Khorasan; which was the focus of light and the rendezvous of the learned. The men of learning have become the victims of the sword. This is a period of famine for science and virtue:"

In summary, the advent of the Mongols marked a turning point in the history of the Islamic Near East in several ways:

The Mongols tolerated no opposition and were careful to destroy any centers of political power independent of their own. Moreover, for some time they clung to the pastoral traditions of the steppe and had little interest in, and no sympathy for, cities or agricultural areas, except as revenue sources. These factors, coupled with their perhaps intentional use of terror as a means of social control, may explain the destructiveness of the Mongol invasions, which saw the obliteration of many cities and their inhabitants and the destruction or neglect of many irrigation works on which the agrarian prosperity of the countryside depended.  This strong nomadic orientation of the early Mongols at first dealt a severe blow to city life and to rural agriculture alike, both of which were slow to recover to former levels of prosperity. Recovery, when it came, often followed new patterns: different cities rose to prominence (such as Ardabil and Qazwin), while some formerly important ones languished or vanished (such as Baghdad and Nishapur). Some once important regions, such as Khorasan, also waned to relative insignificance.

After destroying Baghdad, the savage horde crossed the Euphrates and passed into Mesopotamia, carrying havoc  and slaughter wherever they went. The inhabitants of Edessa, Harran and Nasibin were put to the sword. In Aleppo; fifty thousand people were massacred, and ten thousand women and children were sold as slaves. Harran surrendered on a promise, that the city would be spared but the Mongols destroyed the inhabitants even to the children at the breast of their terrified mothers, The Mongols marched thus westward, carrying destruction everywhere, assisted in their progress by the divisions prevailing among the Muslims themselves, until they were met at Ain Jalout a town below  Nazareth in Palestine, by the celebrated Mamlouk Sultan Baybars, who afterwards became the sovereign of Egypt, and were defeated with terrible slaughter. Baybars pursued the Mongols beyond Aleppo, and Mesopotamia to rid the region of their loathsome presence. 

This victory spared Cairo, which was at this time the main center of Arabic culture, from Mongol devastation. But Hulaku's forces then controlled the majority of the Islamic east.

At this time the son of Ayibak had been deposed by one of his generals named Saif ud-din Qutouz, who had assumed the sovereignty. Qutouz was assassinated shortly after the battle of Ain Jalout, when Baybars was raised to the throne under the title of el-Malik uz-Zahir.

For two years the Sunni world felt keenly and in sorrow the want of a spiritual head  - a want which has been pathetically voiced by el-Suyouti :
 

Baybars appreciated  the necessity of reviving the khalifate, and hence he invited to the khalifate Ahmad (Abu'l Qasim), a scion of the house of Abbas, who had earlier escaped the massacre of his family, to come to Cairo. 

On the arrival of the young prince in the environs of Cairo, the Sultan went forth to meet him with the qadis and officers of state. After his descent had been formally proved before the Chief qadis, he was acknowledged as khalif under the title of al-Mustansir biIllah. 

The first to take the oath of allegiance was the Sultan; next came the Chief qadi Taj ud-din, the principal shaikhs, and lastly the nobles, according to their ranks. This occurred on the 13th of Ragab and the new khalif's name was impressed on the coinage and recited in the Khutbah. The following Friday,  he rode to the mosque in procession, wearing the black mantle, and delivered the religious sermon"

Having been formally installed the khalif of the faithful he proceeded to invest the Sultan with the robe and diploma so essential in the eyes of the orthodox for legitimate authority. 

Thus was revived in Cairo the Abbasid khalifate under the auspices of the warrior Mamlouk Sultan. Henceforth it was a purely spiritual office until the Ottoman invasion in the 16thc. when Sultan Selim the conqueror assumed the title of khalif. 
 
 

(I) Bokhara, which was studded with palaces, parks, and gardens, stretched for miles on both sides of the river Soghd, which traversed its suburbs.