Revolutionary and geographer, born in Moscow, Russia. The son of a prince, he was educated at the Corps of Pages, St Petersburg. He became an army officer and was stationed in Siberia (1862–7), where he made zoological and geographical studies that won him recognition in scientific circles. In 1871 he renounced his title and devoted himself to a life as a revolutionary. Arrested and imprisoned (1874), he escaped to Switzerland in 1876. Expelled from Switzerland in 1881, he went to France, and was condemned in 1883 to five years' imprisonment for anarchism. Released in 1886, he settled in England until the revolution of 1917 took him back to Russia. He wrote of an anarchy where mutual support and trust in a harmonious society is the central theme, not the lawlessness and chaos more usually associated with the term.