[11][12] Khwarazmians ruled large parts of present-day Central Asia, Afghanistan, and Iran from 1077 to 1231; first as vassals of the Seljuk Empire[13] and the Qara Khitai (Western Liao dynasty),[14] and from circa 1190 as independent rulers up until the Mongol conquest in 1219–1221.

The dynasty that ruled the empire was founded by Anush Tigin (also known as Gharachai), initially a Turkic slave of the rulers of Gharchistan, later a Mamluk in the service of the Seljuks.

The Mongols exploited existing weaknesses and conflicts in the empire, besieging and plundering the richest cities, while putting its citizens to the sword in one of the bloodiest wars in human history.

During the uprising in Khwarazm in 1017, rebels killed Khwarazmshah Ma'mun II and his wife Khurra-ji, the sister of Ghaznavid sultan Mahmud of Ghazni.

Anushtegin was put in command together with his master Al-Taj Gümüshtegin in 1073 by the Seljuq sultan Malik-Shah I to retake territory in northern Greater Khorasan that the Ghaznavids had seized.

He died by 1097 and the post was briefly given to Ekinchi bin Qochqar before being transferred to his son, Qutb al-Din Muhammad.

The same year that Sanjar pardoned Atsiz, the Kara Khitai under Yelü Dashi defeated the Seljuqs in the Battle of Qatwan (1141), near Samarqand.

Towards the end of his life, Atsiz subordinated the entire northwestern part of Central Asia, and in fact, achieved its independence from its neighbors.

Initially, Il-Arslan was made governor of Jand, an outpost on the Syr Darya which had recently been reconquered, by his father.

This allowed Il-Arslan to effectively break off Seljuk suzerainty, although he remained on friendly terms with Sanjar's successor, Mas'ud.

He responded by invading the Karakhanid dominions, taking Bukhara and besieging Samarqand, where Chaghri Khan had taken refuge.

The latter appealed to both the Turks of the Syr Darya and the Qara Khitai, and the gurkhan sent an army, but its commander hesitated to enter into conflict with the Khwarazmians.

Following his death the state briefly became embroiled in turmoil, as the succession was disputed between his sons Tekish and Sultan Shah.

Tekish maintained close relations with the Oghuz Turkmens and Turkic Qipchak tribes from the vicinity of the Aral Sea, and recruited them at times for his conquest of Iran.

[31] In 1194, Tekish defeated the Seljuq sultan of Hamadan, Toghrul III, in an alliance with Caliph Al-Nasir, and conquered his territories.

His death triggered spontaneous revolts and widespread massacre of the hated Khwarazmian Turkic soldiers stationed in Iran.

Genghis was looking to open trade relations, but having heard exaggerated reports of the Mongols, the Shah believed this gesture was only a ploy to invade Khwarazm.

[35] Trying to maintain diplomacy, Genghis sent an envoy of three men to the shah, to give him a chance to disclaim all knowledge of the governor's actions and hand him over to the Mongols for punishment.

[36] These events led Genghis to retaliate with a force of 100,000 to 150,000 men that crossed the Jaxartes in 1219 and sacked the cities of Samarqand, Bukhara, Otrar, and others.

This fact, coupled with her conflicts with Muhammad II might have contributed to the impotence of the Khwarazmian Empire in the face of the Mongol onslaught.

He was reportedly the eldest son of Ala ad-Din Muhammad II, while his mother was a Turkmen concubine named Ay Chichek.

He never consolidated his power, however, spending the rest of his days struggling against the Mongols, the Seljuks of Rum, and pretenders to his own throne.

Following on through the Armenian highlands he clashed with the Ayyubids, capturing the town Ahlat along the western shores of Lake Van, which sought the aid of the Seljuq Sultanate of Rûm.

He was the head of the diwan officials (askhab ad-dawawin), who appointed them and established salaries, pensions (arzak), controlling tax administration and the treasury.

[41] An important position in the state apparatus of the Khwarazmshahs was also held by the senior or great hajib, who most of the time, was a representative of the Turkic nobility.

The population of the empire is estimated at 5 million people on the eve of the Mongol invasion in 1220, making it sparse for the large area it covered.

[8][note 1] Historical demographers Tertius Chandler and Gerald Fox give the following estimations for the populations of the empire's major cities at the beginning of the 13th century, which adds up to at least 520,000 and at most 850,000 people.

[46][47] Although the Khwarazmshahs had a Turkic origin, just as their Seljuq predecessors, they adopted Persian culture, adhered to the Sunni branch of Islam and had their richest and most populous cities in Khorasan.

Sultan Jalal ad-Din's followers remained loyal to him even after his death in 1231, and raided the Seljuq lands of Jazira and Syria for the next several years, calling themselves the Khwarazmiyya.