In 1846, Kazakhstan was annexed, bringing the Russian Empire to the Chu river. Beyond the Chu River was the khanate of Khokhand, with its capital at Tashkent. After numerous cattle-raids, enslaving of Russian subjects and retaliatory expeditions, open war broke out in 1853, with a certain Yakub Beg directing Khokhandian efforts in the north-west. The Russian advance was slow and insidious, reaching the Syr Daria only in 1861.
In 1865, Bokhara invaded Khokhandia in order to annex disputed territory. The Russian commander, fearing that the Bokharans would take Tashkent, decided to move on the capital, despite his orders, taking it in June 1865. In 1867, Khokhandia was formally subjected to Russian military governorship.
In 1866, the Boukharans attacked Russian positions on the Syr Darya and marched on Tashkent. War was declared; it took the Russians two years to pacify the khanate, which was stripped in 1868 of a goodly proportion of its territory. It remained however independent until 1920, with an army and autonomous foreign policy.
The khanate of Khiva (ancient Khwarezm) also remained independent until it unwisely supported a Kazakh rebellion in 1869-71. 14,000 Russians penetrated into the khanate in April 1873.
War with Persia followed in 1884-1885, allowing Russian to annexe Merv; during this conflict a border incident came close to drawing Russia into a war with Afghanistan.
The Empire's frontiers in Central Asia had now reached their greatest extension and, with Russian troops at the gates of Afghanistan - and therefore of India - had brought the "Great Game" to the height of tension. Any desire to intervene in Kashgaria had been thwarted by the successful Chinese counter-attack there in 1876-78. War with China was indeed narrowly averted, until the Russians evacuated the Ili valley in 1881.
Instead, the Tsar concentrated on improving his political hold over Persia, which grew steadily until the 1907 settlement with Britain.