Karl Heinrich Marx was a German philosopher, economist, sociologist, historian, journalist and revolutionary socialist (5 May 1818 - 14 March 1883). His ideas played an important role in the foundation of sociology and in the development of socialist movements. Marx was considered one of the greatest economists in history. He published several books during his lifetime, the most important of which are The Manifesto of the Communist Party (1848) and Das Kapital (1867–1894). Born into a wealthy middle-class family in Trier in the Prussian Rhineland, Marx studied at the University of Bonn and the University of Berlin, where he became interested in the philosophical ideas of the Young Hegelians. He was associated with Jenny von Westphalen in 1836 AD, and married her in 1843 AD after his studies. He wrote for a radical newspaper in Cologne, and began to develop his theory of dialectical materialism. After moving to Paris in 1843, he began writing for other radical newspapers.