Russian-speaking. From the late 18th century until the late 19th century, city life was increasingly dominated by Russian military and ecclesiastical concerns. Russian Orthodox Church institutions formed a significant part of the city's infrastructure and business activity at that time. In the winter 1845–1846, the historian Mykola Kostomarov (Nikolai Kostomarov in Russian) founded a secret political society, the Brotherhood of Saints Cyril and Methodius, whose members put forward the idea of a federation of free Slavic people with Ukrainians as a distinct group among them rather than a part of the Russian nation. The Brotherhood's ideology was a synthesis of programmes of three movements: Ukrainian autonomists, Polish democrats, and Russian Decembrists in Ukraine. The society was quickly suppressed by the Tsarist authorities in March–April 1847. Following the gradual loss of Ukraine's autonomy and suppression of the local Ukrainian and Polish cultures, Kiev experienced growing Russification in the 19th century by means of Russian migration, administrative actions (such as the Valuev Circular of 1863), and social modernization. At the beginning of the 20th century, the city was dominated by Russian-speaking population, while the lower classes retained Ukrainian folk culture to a significant extent. According to the census of 1897, of the city's approximately 240,000 people approximately 56% of the population spoke the Russian language, 23% spoke the Ukrainian language, 12.5% spoke Yiddish, 7% spoke Polish and 1% spoke the Belarusian language. Despite the Russian cultural dominance in the city, enthusiasts among ethnic Ukrainian nobles, military and merchants made recurrent attempts to preserve native culture in the city (by clandestine book-printing, amateur theater, folk studies etc.). During the Russian industrial revolution in the late 19th century, Kiev became an important trade and transportation center of the Russian Empire, specializing in sugar and grain export by railroad and on the Dnieper river. By 1900, the city had also become a significant industrial center, having a population of 250,000. Landmarks of that period include the railway infrastructure, the foundation of numerous educational and cultural facilities as well as notable architectural monuments (mostly merchant-oriented, i.e. Brodsky Choral Synagogue). At that time, a large Jewish community emerged in the city, developing its own ethnic culture and business interests. This was stimulated by the prohibition of Jewish settlement in Russia proper (Moscow and Saint Petersburg) — as well as further eastwards. Expelled from Kiev in 1654, Jews probably were not able to settle in the city again