Karl Marx (5 May 1818 - 14 March 1883) was a German philosopher, economist, sociologist, journalist, and revolutionary socialist. Marx's work in economics laid the basis for much of the current understanding of labour and its relation to capital, and subsequent economic thought. He is one of the founders of sociology and social science. He published numerous books during his lifetime, the most notable being The Communist Manifesto (1848) and Das Kapital (1867-1894). Born into a wealthy middle-class family in Trier in the Prussian Rhineland, Marx studied at the Universities of Bonn and Berlin where he became interested in the philosophical ideas of the Young Hegelians. After his studies he wrote for a radical newspaper in Cologne and began to work out the theory of the materialist conception of history. He moved to Paris in 1843, where he began writing for other radical newspapers and met Friedrich Engels, who would become his lifelong friend and collaborator. In 1849 he was exiled and moved to London together with his wife and children, where he continued writing and formulating his theories about social and economic activity. He also campaigned for socialism and became a significant figure in the International Workingmen's Association. Marx's theories about society, economics and politics - the collective understanding of which is known as Marxism - hold that human societies progress through class struggle: a conflict between an ownership class that controls production and a dispossessed labouring class that provides the labour for production. States, Marx believed, were run on behalf of the ruling class and in their interest while representing it as the common interest of all; and he predicted that, like previous socioeconomic systems, capitalism produced internal tensions which would lead to its self-destruction and replacement by a new system: socialism. He argued that class antagonisms under capitalism between the bourgeoisie and proletariat would eventuate in the working class' conquest of political power and eventually establish a classless society, communism, a society governed by a free association of producers. Marx actively fought for its implementation, arguing that the working class should carry out organised revolutionary action to topple capitalism and bring about socio-economic change. Marx has been described as one of the most influential figures in human history. Many intellectuals, labour unions and political parties worldwide have been influenced by Marx's ideas, with many variations on his groundwork.