gold on the banks of the Amu Darya during the reign of Russia's Peter the Great, together with the desire of the Russian Empire to open a trade route to the Indus (modern day Pakistan), prompted an armed trade expedition to the region, led by Prince Alexander Bekovich-Cherkassky, which was repelled by Khiva. Khwarazm during the reign Uzbek dynasty of Qungrats During the reign of the Uzbek Khan Said Muhammad Khan (1856–1864) in the 1850s, for the first time in the history of Khwarazm, a general population census of Khwarazm was carried out. Khwarazm in 1873–1920 It was under Tsars Alexander II and Alexander III that serious efforts to annex the region started. One of the main pretexts for Russian military expeditions to Khiva was to free Russian slaves in the khanate and to prevent future slave capture and trade. Early in The Great Game, Russian interests in the region collided with those of the British Empire in the First Anglo-Afghan War in 1839. The Khanate of Khiva was gradually reduced in size from Russian expansion in Turkestan (including Khwarezm) and, in 1873, a peace treaty was signed that established Khiva as a quasi-independent Russian protectorate. In 1912, the Khiva Khanate numbered up to 440 schools and up to 65 madrasahs with 22,500 students. More than half of the madrasahs were in the city of Khiva (38). Soviet period After the Bolshevik seizure of power in the October Revolution, a short-lived Khorezm People's Soviet Republic (later the Khorezm SSR) was created out of the territory of the old Khanate of Khiva, before in 1924 it was finally incorporated into the Soviet Union, with the former Khanate divided between the new Turkmen SSR, Uzbek SSR and Karakalpakstan ASSR (initially part of Kazakh ASSR as Karakalpak Oblast). The larger historical area of Khwarezm is further divided. Northern Khwarezm became the Uzbek SSR, and in 1925 the western part became the Turkmen SSR. Also, in 1936 the northwestern part became the Kazakh SSR. Following the collapse of the Soviet Union in 1991, these became Uzbekistan, Turkmenistan and Kazakhstan respectively. Many of the ancient Khwarezmian towns now lie in Xorazm Region, Uzbekistan. Today, the area that was Khwarezm has a mixed population of Uzbeks, Karakalpaks, Turkmens, Tajiks, Tatars, and Kazakhs. In Persian literature Khwarezm and her cities appear in Persian literature in abundance, in both prose and poetry. Dehkhoda for example defines the name