Why did some Kazakh hordes accept Russian protection in the 18th century?

In the 18th century, the three Kazakh hordes—the Little, Middle, and Great—accepted Russian protection primarily to gain security against the aggressive raids of the Dzungars, a federation of western Mongol tribes.12

During this period, the Kazakhs faced significant military pressure from the Dzungars, including a devastating invasion in 1723 known as the "Great Disaster". As the Kazakh khanate had become politically fragmented into three separate hordes, their central authority was often weak, making them vulnerable to these external threats. Some Kazakhs believed that establishing a formal relationship with the Russian Empire would provide a necessary defense against the Dzungar incursions.32

Consequently, the Little Horde accepted Russian protection in 1731, followed by the Middle Horde in 1740 and part of the Great Horde in 1742. While this submission was intended to secure protection, the actual effect on the Dzungar threat proved to be minimal. Over time, this initial move toward Russian protection facilitated further Russian expansion into Kazakhstan, eventually leading to the suppression of the autonomy of all three hordes by the mid-19th century.21