Qabacha initially retreated, but Iltutmish's army chased him and defeated him at a place called Mansura, which was located on the banks of the Chenab River. Iltutmish then captured Lahore in the winter of 1216–1217, and appointed his son Nasiruddin Mahmud to govern it. Lahore remained contested in the subsequent years; for example, at the time of Khwarazmian invasion of the region (see below), it was under the control of Qabacha's son. Qabacha seems to have posed a serious threat to Iltutmish, as suggested by Muhammad Aufi in Lubab ul-Albab. Aufi, writing shortly before the Khwarazmian invasion, expresses hope that his patron Qabacha will soon conquer the whole of Hindustan. Aufi also mentions that Ahmad Jamaji, who was Iltutmish's governor of Bahraich, defected to Qabacha in 1220. Khwarazmian threat The Khwarazmshahs, who had taken over the western part of the former Ghurid Empire, suffered a Mongol invasion in 1220. After being defeated at the Battle of Indus in 1221, the Khwarazmshah Jalal ad-Din Mingburnu escaped to the Punjab region. He entered into a matrimonial alliance with the local Khokhar chief Rai Khokhar Sankin, and defeated other regional rulers, including Qabacha. The Mongol leader Genghis Khan briefly considered returning to Mongolia through a shorter route which involved crossing the Himalayan foothills. He sent envoys to Iltutmish, asking for the Delhi Sultan's permission to pass through India. No extant sources provide any information about the result of this embassy, but it appears that Genghis Khan abandoned his plan to pass through India. According to the Persian historian Ata-Malik Juvayni, Genghis Khan advanced eastwards into India, but failed to find a suitable route, and therefore, exited the country via Peshawar. It is possible that Genghis Khan, through his envoys, asked Iltutmish to not aid Jalal ad-Din: Iltutmish seems to have obliged. Meanwhile, Jalal ad-Din established himself in the Sindh Sagar Doab in the Punjab region, and captured the fort of Pasrur. He sent his envoy Ainul Mulk to Iltutmish, seeking an alliance against the Mongols, and requesting for a safe place to stay. According to Juvayni, after deliberating over the matter for several days, Iltutmish refused to provide him a residence on the excuse that no place in his kingdom have a suitable climate or a locality fit for a king. Iltutmish also had the envoy killed, and sent troops to aid Qabacha against Jalal ad-Din . Minhaj, another Persian historian, states that