Political, territorial and military circumstances on the eve of the invasion Territorial expansion of Khwarazmians under Muhammad II and confrontation with Abbasid Caliph al-Nasir After the fall of the
Seljuks of
Persian Iraq, with the defeat of
Toghrul III by
Ala al-Din Tekish (the father of Shah
Muhammad), a severe enmity arose over the governance of
Western Iran between the Abbasid caliph
al-Nasir and Ala al-Din Tekish. These conflicts continued during the reign of Shah Muhammad, and Western Iran became the battleground of the Khwarazmian troops and the caliphate troops. In order to destroy the
Khwarazmian Empire, Al-Nasir not only provoked the
Ghurids and orthodox religious scholars from
Transoxiana against it, but also asked help from the
Nizari Ismaili state, the
Qara Khitai and
Mongol tribes. These actions eventually not only led to the overthrow of the Khwarazmian Empire, but also the subsequent overthrow of the Abbasid government. Simultaneously with the coronation of
Shah Muhammad, the Ghurids captured the remaining lands of the
Ghaznavids and
Khorasan cities such as
Balkh. Shah Muhammad defeated the Ghurid dynasty in 1212 and captured
Ghazni in 1215, thus he extended the border of his territory to
India from the east. In 1209, he conquered
Mazandaran, which had been held by the
Bavands for a long time. In the 12th century, a group of
Khitan people from
North China who were
Buddhists, had formed a large political entity in the province of
Kashgar and
Hotan called
Qara Khitai. In order to block their expansionism, the Khwarazmians had agreed to pay them a yearly tribute. This custom continued until the times of Shah Muhammad, but then he refused to pay tribute to the "polytheist" king. Shah Muhammad fought three times with the Qara Khitai. At last in 1210, the Shah asked for help from
Kuchlug, a prince and leader of the
Naimans, in order to defeat the Qara Khitai. Kuchlug defeated them in
Transoxiana and conquered
Bukhara and
Samarkand, usurping the Qara Khitai Empire from his father-in-law
Yelü Zhilugu. After conquering Transoxiana, Kuchlug alienated both his subjects and the Khwarazmian Empire with anti-Muslim measures. As a Mongol detachment led by
Jebe hunted Kuchlug down, he fled; meanwhile, Muhammad was able to
vassalize the territories of
Balochistan and
Makran in modern-day
Pakistan and
Iran, and to gain the allegiance of the
Eldiguzids. After extending the borders of the Khwarazmian Empire from the north-east and east to
Kashgar and the
Sindh, Shah Muhammad decided to conquer the west, i.e.
Iraq. At that time, these lands were in the hands of the Eldiguzids and
Salghurids, and the authority of the Abbasid caliph's clergymen remained partly in these two regions. Shah Muhammad was at enmity with the Abbasid caliph, because the caliph asked for help from the Ismailis and the Qara Khitai to overthrow his rule and also because the shah wanted the authority of the Khwarazmians sentence in
Baghdad. As a result of this dispute and enmity, Shah Muhammad received a
fatwa from the scholars of his country that "
Bani Abbas" do not deserve the caliphate and one of "Husayni Sadat" (a person from the generation of
Imam Husayn) should be chosen for this position. Therefore, he declared the caliph deposed and ordered that the name of the Abbasid caliph should not be mentioned in sermons and not be inserted on coins, and appointed one of the
Termezi Alawi Sadats, as the caliphate. In 1217, Shah Muhammad marched towards Baghdad, but because it was winter, his troops suffered a lot from the snow and cold in the Asadabad pass between
Kermanshah and
Hamadan, and thus he returned to Khorasan. In this way, the first ambassador of Shah Muhammad was accepted in Beijing, and Genghis declared trade between the Mongols and Khwarazmians as a necessity for establishing friendly relations. During this situation, a number of Muslim merchants from Shah Muhammad's territory took some goods to the Mongol Empire, and although Genghis treated them violently at the beginning of their arrival, he finally appeased them and sent them back with respect. At the time that they were returning in 1218, a number of Mongol merchants, whose number reached 450 and apparently most of them were Muslims, was sent by Genghis with some goods and a letter containing his advice and request to establish relations between the two governments. But
Inalchuq, the ruler of
Otrar who was the nephew of
Terken Khatun (Shah Muhammad's mother) and supported by her, was greedy for the wealth of the merchants and arrested the Mongol merchants on the charge of espionage on the border of the territory under his rule, and then with the permission of Shah Muhammad, who was in
Persian Iraq at that time, massacred all these merchants. Then the officials of the Khwarazmian Empire sold the cargo of the caravan, which included 500 camels of gold, silver, Chinese silk artefacts, precious skins and such on, and sent the resulting amount to the capital of the Khwarazmian government. When the news of Otrar incident reached Genghis Khan, he decided to control his anger and made his last attempt to gain satisfaction through diplomacy. He sent a Muslim, who was previously in the service of
Ala al-Din Tekish and was accompanied by two Mongols, to protest against the performance of Inalchuq and requested to surrender him to the Mongols. Shah Muhammad didn't want to surrender Inalchuq because most of the leaders of the Khwarazmian army were his relatives, and also Terken Khatun who had influence in the Khwarazmian court was supporting him. Therefore, Shah Muhammad not only did not accept Genghis Khan's request, but also executed his Muslim envoy who came to
Samarkand, the capital of the Khwarazmian Empire, and sent his companions back to Genghis Khan with their beards and mustaches cut off. This bellicose behavior of Shah Muhammad accelerated the
Mongol invasion of Central Asia. Historians cite the fact that Genghis was already bogged down in
his war against the Jin in China, and that he had to deal with the
Hoi-yin Irgen rebellion in
Siberia in 1216, so he didn't want to start another war.
Economic factors The Mongols had a need for the goods of more advanced regions; therefore, it was very important for them to keep trade routes open since ancient times. ==Genghis' campaign==