Jahan, assisted by Kamran Khanand Malik Maghdood, had marched on Kandahar and negotiated the surrender from the Persian commander, Ali Mardan Khan. He expected the Persians to attempt to regain the city soon and so he ordered that the wall be repaired rapidly while a large Mughal army based in Kabul protected the area. In 1646, when no Persian attack came, the Emperor sent his son, Murad Baksh, to invade Uzbek-controlled Badakhshan. In the following year, Aurangzeb, another son, routed an Uzbek force outside of Balkh and captured the city. Though victorious in the field, the Mughals were unable to secure the conquered territories and Shah Jahan was forced to recall his armies from Badakhshan. War On 4 April 1648, encouraged by the Mughal reversal in Badakhshan, Shah Abbas II marched from Isfahan with an army of 40,000. After capturing Bost, he laid siege to Kandahar on 28 December and easily captured it after a brief siege on 22 February 1649. The disaster of the Balkh campaign had gravely weakened the Mughals' position on the frontier. The short duration of the Kandahar siege – two months – stands testament to the vulnerability of the Mughals in Afghanistan. The Mughals attempted to retake the city in 1651 but the arrival of winter forced them to suspend the siege. Sieges of Kandahar Shah Jahan sent Aurangzeb with 50,000 soldiers to recapture it, but although he defeated the Safavids outside the city he was unable to take it. His artillery train proved unable for the task. Aurangzeb attempted to take the fortress city again in 1652. Abdul Aziz, Khan of Bukhara, had entered into an alliance with Shah Abbas and in May 1652, he dispatched 10,000 troops to Kabul in May to harass the Mughal supply lines. Though not strong enough to lift the siege, the Uzbeks endangered a Mughal convoy of 2,000 who were escorting one and a half million silver coins to the besieger's army at Kandahar. After two months of fighting Persian resistance and the growing activities of the Uzbeks, Aurangzeb was forced to abandon the campaign. In 1653 Shah Jahan sent Dara Shikoh, with a large army and two of the heaviest artillery pieces of the empire, but after a five-month siege the Mughals couldn't manage to starve the city, and the attempt to breach their walls by cannon fire also failed. The Mughals finally gave up all attempts