Decembrist revolt Nicholas I Crimean War tsar
The officers who pursued Napoleon into Western Europe brought ideas of liberalism back to Russia, and attempted to curtail the tsar's powers during the abortive Decembrist revolt of 1825. At the end of the conservative reign of Nicholas I (1825–1855), a zenith period of Russia's power and influence in Europe, was disrupted by defeat in the Crimean War.
