The Uzbek Khanate (Uzbek: Oʻzbek xonligi or Oʻzbek ulusi), also known as the Abulkhair Khanate was a Shaybanid state preceding the Khanate of Bukhara. During the few years it existed, the Uzbek Khanate was the preeminent state in Central Asia, ruling over most of modern-day Kazakhstan, much of Uzbekistan and Turkmenistan, and parts of southern Russia. This is the first state of the Abulkhairids, a branch of the Shaybanids.
The dynasty of Abu’l-Khayr Khan and his descendants is named after him, and the states ruled by them are known as Abulkhairids, such as in the Khanate of Bukhara. They may also be referred to as Shaybanids, although this is more of an umbrella term as a rival dynasty called the Arabshahids of Khwarezm were also Shaybanids, but not Abulkhairids.
Starting with Shiban, brother of Batu Khan who was the ruler of the Golden Horde, the Shaybanids and their descendants held land and sway over many tribes granted to Shiban by Batu. These lands included the Golden Horde domains east of the Urals, and lands north of the Syr Darya river. Central control in the Golden Horde eroded away quickly in the east and breakaway states like the Nogai Horde and the Khanate of Sibir appeared in the region.
By the time of Abu’l-Khayr’s birth in 1412, the ulus of Shiban was fractured. At this time the eastern part of the Golden Horde (The Blue Horde) had become outside of complete control of the Golden Horde khans and pretenders, especially after the assassination of Barak Khan in 1427. Abu’l-Khayr was taken prisoner after a battle in 1427 and was released in 1428. After the passing of the then Khan of the Uzbeks and pretender to the throne of the Golden Horde, Barak Khan, Ulug Beg, the leader of the Timurid Empire, secretly orchestrated the title of khan to pass to Abu’l-Khayr. He began his rule by consolidating tribes in Siberia around his capital at Chimgi-Tura (Modern-day Tyumen). He was able to depose the reigning Khan of Sibir, Kazhy Mohammed, and took the entirety of the area under Shaybanid control.
Abu’l-Khayr invaded the Golden Horde sometime after this and defeated Mustafa Khan near Astrakhan. The Uzbeks lost around 4,500 men during this campaign.
Prior to the death of Shah Rukh in 1448 Sighnaq and other cities in Turan such as Uzkend and Sozak were invaded and captured by the Uzbeks. Sighnaq became one of the principal cities of Central Asia during this time.
In 1451 Abu’l-Khayr allied with the Timurid Abu Sa’id against his rival ‘Abdullah and the two both marched on Samarkand. The Uzbek-Abu Sa’id alliance was successful and in return Abu Sa’id paid tribute to the Uzbeks.