Alexander II, 1818–81, Tsar of Russia (1855–81), son and successor of Nicholas I. He ascended the throne during the Crimean War (1853–56) and immediately set about negotiating a peace. Influenced by Russia's defeat in the war and by peasant unrest Alexander embarked upon a modernization and reform program. The most important reform was the emancipation of the serfs (1861). This failed, however, to meet the land needs of the newly freed group and created many new problems. In 1864, a system of limited local self-government was introduced (zemstvo) and the judicial system was partially westernized. Municipal government was overhauled (1870), universal military training was introduced (1874), and censorship and control over education were temporarily relaxed. In Poland, Alexander initially adopted a moderate policy, granting the subject nation partial autonomy. When revolt broke out in 1863, however, Alexander reacted with brutal suppression, imposing severe Russification. The Western powers were sharply warned against interference. Prussia's support of Russia during this diplomatic crisis led to a Russo-Prussian rapprochement, and in 1872 the Three Emperors' League was formed by Russia, Prussia, and Austria-Hungary. Throughout his reign Alexander promoted vigorous expansion in the East. The conquest of the Ussuri region in East Asia was confirmed by the Treaty of Beijing (1860) with China. Central Asia was added to Russia by the conquest of Kokand, Khiva, and Bokhara (1865–76). Alaska, however, was sold (1867) to the United States. In 1877–78 Russia waged war on Turkey, ostensibly to aid the oppressed Slavs in the Balkans. Meanwhile, in domestic affairs, Alexander's reforms, while outraging many reactionaries, were regarded as far too moderate by the liberals and radicals. Radical activities increased sharply among the intelligentsia, resulting in a reassertion of repressive policies. When the populist, or “to the people” movement arose in the late 1860s (narodniki), the government arrested and prosecuted hundreds of students. Many radicals responded with terrorist tactics. In 1881, after several unsuccessful attempts, a member of the People's Will, a terrorist offshoot of the populist movement, assassinated Alexander with a hand-thrown bomb; this on the very day (Mar. 13) that Alexander had signed a decree granting the zemstvos an advisory role in legislation. He was succeeded by his son Alexander III.