Abbasid suzerainty. In 892, Ismail Samani (892–907) united the Samanid state under one ruler, thus effectively putting an end to the feudal system used by the Samanids. It was also under him that the Samanids became independent of Abbasid authority. The Kara-Khanid Khanate conquered Transoxania (which corresponds approximately with modern-day Uzbekistan, Tajikistan, southern Kyrgyzstan, and southwest Kazakhstan) and ruled between 999 and 1211. Their arrival in Transoxania signalled a definitive shift from Iranian to Turkic predominance in Central Asia, but gradually the Kara-khanids became assimilated into the Perso-Arab Muslim culture of the region. In the 13th century, the Mongol Empire swept through Central Asia, invaded Khwarezmian Empire and sacked the cities, looting and massacring people everywhere. Turco-Mongol conqueror Tamerlane founded the Timurid Empire in and around modern-day Tajikistan and Central Asia, becoming the first ruler of the Timurid dynasty. Bukharan rule Modern Tajikistan fell under the rule of the Khanate of Bukhara during the 16th century and with the empire's collapse in the 18th century it came under the rule of both the Emirate of Bukhara and Khanate of Kokand. The Emirate of Bukhara remained intact until the 20th century but during the 19th century, for the second time in world history, a European power (the Russian Empire) began to conquer parts of the region. Imperial Russia Russian Imperialism led to the Russian Empire's conquest of Central Asia during the late 19th century's Imperial Era. Between 1864 and 1885, Russia gradually took control of the entire territory of Russian Turkestan, the Tajikistan portion of which had been controlled by the Emirate of Bukhara and Khanate of Kokand. Russia was interested in gaining access to a supply of cotton and in the 1870s attempted to switch cultivation in the region from grain to cotton (a strategy later copied and expanded by the Soviets). By 1885 Tajikistan's territory was either ruled by the Russian Empire or its vassal state, the Emirate of Bukhara, nevertheless Tajiks felt little Russian influence. During the late 19th century, the Jadidists established themselves as an Islamic social movement throughout the region. Although the Jadidists were pro-modernization and not necessarily anti-Russian, the Russians viewed the movement as a threat because the Russian Empire was predominantly Christian. Russian troops were required to restore order during uprisings against the Khanate of Kokand between 1910 and 1913. Further violence occurred in July 1916 when demonstrators attacked Russian soldiers in Khujand over