In 1845, Alexander II began his reign as Tsar of Russia and presided over a period of political and social reform, notably the emancipation of serfs in 1861 and the lifting of censorship. His successor Alexander III (1881–1894) pursued a policy of repression and restricted public expenditure, but continued land and labour reforms. This was a period of population growth and significant industrialization, though Russia remained a largely rural country. Political movements of the time included the Populists (Narodniki), anarchists and Marxists. A revolutionary organization called People's Will (Narodnaya Volya) assassinated Alexander II. Another current of thought was embodied in the Slavophiles, who opposed modernization and Westernization. Russia continued to expand its empire, occupying the Caucasus, Tashkent and Samarkand. In foreign affairs, the period began with the conclusion of the Crimean War. Russian policy brought it into conflict with other European powers, in particular Austria-Hungary, as it sought to extend influence over the European portions of the receding Ottoman Empire and regain naval access to the Black Sea. This culminated in a successful war with the Ottoman Empire in 1877–1878, followed by the Treaty of San Stefano and Congress of Berlin in 1878 by which an independent Bulgaria came into being and by acquisition of former Ottoman territories in the South Caucasus. Russia joined Germany and Austria-Hungary in the League of the Three Emperors, but friction continued with both partners over Bulgaria. The alliance with Germany came to an end in 1890. Economic development Russia's population growth rate from 1850 to 1910 was the fastest of all the major powers except for the United States. Between 1850 and 1900, Russia's population doubled, but it remained chiefly rural well into the twentieth century. The proclamation law of 1861 freed the peasants from dependence on the landowners and granted them all the land, previously worked by the peasants for their own use. Agriculture remained in the hands of peasants, who together constituted about four-fifths of the rural population, and former landowners. By the end of 19th century, Russia was the largest producer and exporter of cereals in the world. Owing to the development of agriculture, Russia gradually assumed a more important position in the world trade. Industrial growth was significant, although unsteady, and in absolute terms it was not extensive. Russia's industrial regions included Moscow, the central regions of European Russia, St. Petersburg, the Baltic cities, Russian Poland, some areas along the