The German philosopher, radical economist, and revolutionary leader Karl Marx (1818-1883) founded modern "scientific" socialism. His basic ideas--known as Marxism--form the foundation of socialist and communist movements throughout the world.

Karl Marx spent most of his life in exile. He was exiled from his native Prussia in 1849 and went to Paris, from which he was expelled a few months later. He then settled in London, where he spent the rest of his life in dire poverty and relative obscurity. He was hardly known to the English public in his lifetime. His reputation as a radical thinker began to spread only after the emergence of the socialist parties in Europe, especially in Germany and France, in the 1870s and 1880s. From then on, Marx's theories continued to be hotly debated in the growing labor and socialist movements everywhere, including Czarist Russia.

By the end of the 19th and beginning...