The third son of Paul I, he succeeded his brother Alexander I, having crushed a revolt by the Decembrists, who favoured his elder brother Constantine. His rule was authoritarian and allowed for little social reform. Russia was ruled by the army bureaucracy and police, intellectual opposition only expressed itself in study circles and secret societies. These groups polarized into “Slavophiles”, who held that Russian civilization should be preserved through the Orthodox Church and the village community, and “Westernizers” who wished to see western technology and liberal government introduced. Nicholas embarked on the Russo-Turkish Wars and brutally suppressed the uprising (1830–31) in Poland. Religious minorities, including Jews, were persecuted. In the Revolutions of 1848 he helped Austria crush the nationalists in Hungary, and his later attempts to dominate Turkey led to the Crimean War (1853–56). He was succeeded by his son Alexander II.