Sultan Ahmad, the Khan of Moghulistan, having written several times to ask Baber's permission for the boy to be sent to him, at last obtained it, and Mirza Haidar, "led away by youthful impatience," as he himself writes, availed himself of the Emperor's consent, unwillingly given, and followed his uncle to Andiján, then the capital of Farghána.
It was about the beginning of the year 1514 that Mirza Haidar arrived at Andiján, and almost immediately afterwards entered the service of his kinsman Sultan Said Khan (the son of Sultan Ahmad), who had just then been conducting an expedition against the Uzbegs in Tashkand, but had returned to Andiján on the enemy evacuating their positions. During the following summer, however, the Uzbegs recovered themselves and marched with a large force to lay siege to the Farghana capital. Sultan Said convened a council of his chiefs, who were unanimously of opinion that they were unable, without allies, to contend against the power of the Uzbegs; they believed themselves to have a fairer chance of success by undertaking an invasion of Kashghar, and wresting that province from Mirza Abá Bakr, who then held it. This resolution was accordingly adopted, and before the Uzbegs had time to enter the country, the Khan with all his Amirs, their families and baggage, set out from Andiján and advanced towards Kashghar, by a route leading through Moghulistan. This Mirza Abá Bakr was of the line of Dughlát Amirs, and was regarded by the Khans of Moghulistan as a usurper. He was an active and able soldier, though a cruel tyrant, and during his long rule, had made himself master of nearly the whole of Eastern Turkistan, besides several of the neighbouring countries. In 1511 he had invaded Farghána, but had there received a check by coming into conflict with Sultan Said, from whose forces he experienced a severe defeat at the battle of Tutluk, near Andiján. It was this victory over the usurper, that emboldened Sultan Said and his Amirs to attack him again in his own stronghold. Their enterprise resulted in a complete success: Kashghar was taken in 1514, while Yangi-Hisar, Yarkand, and the remainder of the cities of Eastern Turkistan fell shortly afterwards. Aba Bakr, driven an exile to Ladak, was murdered on the road, and the line of Moghul Khans was re-established in Moghulistan and Eastern Turkistan.
Mirza Haidar, though now only fifteen years of age, was raised by his cousin the Khan to a high position, and his life of activity
