Absolutism is a form of government where one person or small group of people have unlimited power. The term "czar" means "caesar" ("king"), and therefore can be considered a type of absolute ruler. Ivan the Great of Russia (r.1462-1505) took the title of "czar" after marrying the niece of the last Byzantine empire. After the fall of Constantinople (and thus, the Byzantine Empire), Moscow became the most powerful city in the Eastern Orthodox Church. Thus, the "czar" of Russia would from then on claim to be the inheritor of the Byzantine emperor and protector of the Eastern Orthodox Church.
Two rulers of Russia stand out as being "absolute rulers": Peter the Great (r.1682-1725) and Catherine the Great (r.1762-1796). Peter wanted to make Russia into a modern nation, and forced Russians to adopt European culture. To do this, Peter created a new class of nobles that were given land in exchange for their loyalty to the government. Nobles were given total control over their peasants, who saw their freedom decrease during Peter's rule. To reform the government, Peter created a centralized bureaucracy of non-elected advisers and local governments were placed under the direct control of the czar. Peter also brought the Orthodox Church under his authority and created a council of bishops appointed by him. While many of Peter's policies improved the Russian economy, he divided the Russian people. (See image: Courtesy of saint-petersburg.com)
Catherine the Great began her rule by seizing power from her own husband! Catherine greatly admired Peter I and continued to expand and modernize Russia. Many people consider Catherine's reign a golden age of Russia because she supported the arts, education, and culture. Despite being influenced by the European enlightenment, Catherine feared chaos and peasant uprisings were brutally crushed by her army. She allowed nobles to treat their serfs (peasants) however they wished. More peasants than ever were forced into serfdom than ever before, and their position worsened.
