Pyotr Alexeyevich Kropotkin (9 December 1842[a] - 8 February 1921) was a Russian activist, writer, revolutionary, scientist, economist, sociologist, historian, essayist, researcher, political scientist, biologist, geographer[11] and philosopher who advocated anarcho-communism. Born into an aristocratic land-owning family, he attended a military school and later served as an officer in Siberia, where he participated in several geological expeditions. He was imprisoned for his activism in 1874 and managed to escape two years later. He spent the next 41 years in exile in Switzerland, France (where he was imprisoned for almost four years) and in England. While in exile, Kropotkin gave lectures and published widely on anarchism and geography.[12] He returned to Russia after the Russian Revolution in 1917 but was disappointed by the Bolshevik state. Kropotkin was a proponent of a decentralised communist society free from central government and based on voluntary associations of self-governing communities and worker-run enterprises. He wrote many books, pamphlets, and articles, the most prominent being The Conquest of Bread and Fields, Factories and Workshops; and his principal scientific offering, Mutual Aid: A Factor of Evolution. He also contributed the article on anarchism to the Encyclopædia Britannica Eleventh Edition[13] and left unfinished a work on anarchist ethical philosophy. Pyotr Kropotkin was born in Moscow, into an ancient Russian princely family. His father, major general Prince Alexei Petrovich Kropotkin, was a descendant of the Smolensk branch,[14] of the Rurik dynasty which had ruled Russia before the rise of the Romanovs. Kropotkin's father owned large tracts of land and nearly 1,200 male serfs in three provinces.[15] His mother was the daughter of a Cossack general.[15] "Under the influence of republican teachings", Kropotkin dropped his princely title at age 12, and "even rebuked his friends, when they so referred to him."[16] In 1857, at age 14, Kropotkin enrolled in the Corps of Pages at St. Petersburg.[17] Only 150 boys - mostly children of nobility belonging to the court - were educated in this privileged corps, which combined the character of a military school endowed with exclusive rights and of a court institution attached to the Imperial Household. Kropotkin's memoirs detail the hazing and other abuse of pages for which the Corps had become notorious.