a punitive expedition to obtain their submission. In 1197, Muhammad bin Bakhtiyar Khalji, a Khalaj general from Garmsir, Helmand in the army of the Ghurid Sultan Muhammad of Ghor, captured Bihar in India, and then became the ruler of Bengal, beginning the Khalji dynasty of Bengal (1204-1227). During the time of the Mongol invasion of Khwarezmia, many Khalaj and Turkmens gathered in Peshawar and joined the army of Saif al-Din Ighraq, who was likely a Khalaj himself. This army defeated the petty king of Ghazni, Radhi al-Mulk. The last Khwarazmian ruler, Jalal ad-Din Mingburnu, was forced by the Mongols to flee towards the Hindu Kush. Ighraq's army, as well as many other Khalaj and other tribesmen, joined the Khwarazmian force of Jalal ad-Din and inflicted a crushing defeat on the Mongols at the 1221 Battle of Parwan. However, after the victory, the Khalaj, Turkmens, and Ghoris in the army quarreled with the Khwarazmians over the booty, and finally left, soon after which Jalal ad-Din was defeated by Genghis Khan at the Battle of the Indus and forced to flee to India. Ighraq returned to Peshawar, but later Mongol detachments defeated the 20,000–30,000 strong Khalaj, Turkmen, and Ghori tribesmen who had abandoned Jalal ad-Din. Some of these tribesmen escaped to Multan and were recruited into the army of the Delhi Sultanate. Jalal-ud-din Khalji (1290-1296), who belonged to the Khalaj tribe from Qalati Khalji, founded the Khalji dynasty, which replaced the Mamluks and became the second dynasty to rule the Delhi Sultanate. 13th-century Tarikh-i Jahangushay, written by historian Ata-Malik Juvayni, narrated that a levy comprising the "Khalaj of Ghazni" and Pashtuns were mobilized by the Mongols to take part in a punitive expedition sent to Merv in present-day Turkmenistan. Transformation of the Afghan Khalaj The Khalaj were sometimes mentioned alongside Pashtun tribes in the armies of several local dynasties, including the Ghaznavids (977–1186). Many of the Khalaj of the Ghazni and Qalati Ghilji region became assimilated into the local Pashto-speaking population and they likely formed the core of the Pashtun Ghilji tribe. They intermarried with the local Pashtuns and adopted their manners, culture, customs, and practices, also bringing their customs and culture to India where they established the Khalji dynasty of Bengal (1204–1227) and the Khalji dynasty of Delhi (1290–1320). Minorsky noted: "In fact, there is absolutely nothing astonishing in a tribe of nomad habits changing its language. This happened with the