also read in his name. Annexation of Qabacha's empire During the first half of the 1220s, Iltutmish had avoided Indus River Valley, which was contended by the Mongols, the Khwarazm kings, and Qabacha. After the decline of the Mongol and the Khwarazmian threat, Qabacha gained control over this region. Shortly after, during 1228–1229, Iltutmish invaded Qabacha's territory. By this time, the conflicts the Khwarazmians and the Mongols had weakened Qabacha's power. The writings of Hasan Nizami and Muhammad Aufi suggest that Qabacha had earlier signed some treaties with Iltutmish, probably to secure his support against the Khwarazm prince Jalal ad-Din. These treaties probably involved Qabacha's recognition of Iltutmish's sovereignty, or promises to surrender some territories to the Delhi Sultan. Qabacha's failure to abide by these treaties may have prompted Iltutmish to wage a war against him. Iltutmish's forces captured Tabarhinda, Kuhram, Sarsati (or Sursuti), and Lahore from Qabacha. Iltutmish appointed Nasir al-Din Aytemur al-Baha'i as his provincial governor (muqta) of Lahore. He then sent Nasir al-Din to capture Multan, while he himself invaded Uch. Nasir al-Din captured Lahore, and Iltutmish captured Uch after a three-month long siege, on 4 May 1228. Qabacha fled to Bhakkar, pursued by an army led by Iltutmish's wazir Nizam al-Mulk Junyadi. Finding himself in an unwinnable situation, Qabacha sent his son Malik Alauddin Bahram to Iltutmish, to negotiate a peace treaty. Iltutmish offered peace in exchange for Qabacha's unconditional surrender, but Qabacha preferred death to these terms, and committed suicide by drowning himself into the Indus River on the night of 26 May 1228. Iltutmish then placed Multan and Uch under his own governors, and had his forces occupy several strategic forces, expand his authority up to Makran in the west. Malik Sinanuddin, the wāli (governor) of coastal Sindh, also recognized Iltutmish's authority, and thus Iltutmish's empire spread as far as the Arabian Sea. Qabacha's son and surviving followers also accepted Iltutmish's suzerainty. Later years Caliph's recognition In 1220-, the Abbasid Caliph Al-Nasir sent his Indian-born ambassador Radi al-Din Abu'l-Fada'il al-Hasan bin Muhammad al-Saghani to Delhi. The ambassador returned to the Abbasid capital Baghdad in 1227, during the reign of Al-Mustansir. In 1228, the new Caliph sent the ambassador back to Delhi with robes of honour, recognizing Iltutmish's authority in India and conferring on him the titles Yamin Khalifat Allah ("Right Hand of the God's Deputy") and Nasir Amir al-Mu'minin ("Auxiliary of the Commander of