The present-day Kazaks became a recognizable group in the mid-fifteenth century, when clan leaders broke away from Abul Khayr, leader of the Uzbeks, to seek their own territory in the lands of Semirech'ye, between the Chu and Talas rivers in present-day southeastern Kazakhstan. The first Kazak leader was Khan Kasym (r. 1511-23), who united the Kazak tribes into one people. In the sixteenth century, when the Nogai Horde and Siberian khanates broke up, clans from each jurisdiction joined the Kazaks. The Kazaks subsequently separated into three new hordes: the Great Horde, which controlled Semirech'ye and southern Kazakhstan; the Middle Horde, which occupied north-central Kazakhstan; and the Lesser Horde, which occupied western Kazakhstan.

Russian traders and soldiers began to appear on the northwestern edge of Kazak territory in the seventeenth century, when Cossacks established the forts that later became the cities of Oral (Ural'sk) and Atyrau (Gur'yev). Russians were able to seize Kazak territory because the khanates were preoccupied by Kalmyk invaders of Mongol origin, who in the late sixteenth century had begun to move into Kazak territory from the east. Forced westward in what they call their Great Retreat, the Kazaks were increasingly caught between the Kalmyks and the Russians. In 1730 Abul Khayr, one of the khans of the Lesser Horde, sought Russian assistance. Although Abul Khayr's intent had been to form a temporary alliance against the stronger Kalmyks, the Russians gained permanent control of the Lesser Horde as a result of his decision. The Russians conquered the Middle Horde by 1798, but the Great Horde managed to remain independent until the 1820s, when the expanding Quqon (Kokand) Khanate to the south forced the Great Horde khans to choose Russian protection, which seemed to them the lesser of two evils.

The Kazaks began to resist Russian control almost as soon as it became complete. The first mass uprising was led by Khan Kene (Kenisary Kasimov) of the Middle Horde, whose followers fought the Russians between 1836 and 1847. Khan Kene is now considered a Kazak national hero.

Data as of March 1996