Detailed Instructions: This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
Problem: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).[citation needed] 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.[citation needed]
Solution:
When did the Russian Empire take over Central Asia?