History of economic thought died, Engels completed the second volume of "Das Kapital" from his notes. Marx wrote his magnum opus "Das Kapital" (1867) at the British Museum's library in London. Karl Marx begins with the concept of commodities. Before capitalism, says Marx, production was based on slavery – in ancient Rome for example – then serfdom in the feudal societies of medieval Europe. The current mode of labor exchange has produced an erratic and unstable situation allowing the conditions for revolution. People buy and sell their labor as people buy and sell goods and services. People themselves have become disposable commodities. As Marx
Karl Marx move to Germany, Marx decided to emigrate to Brussels in Belgium in February 1845. However, to stay in Belgium he had to pledge not to publish anything on the subject of contemporary politics. In Brussels, Marx associated with other exiled socialists from across Europe, including Moses Hess, Karl Heinzen and Joseph Weydemeyer. In April 1845, Engels moved from Barmen in Germany to Brussels to join Marx and the growing cadre of members of the League of the Just now seeking home in Brussels. Later, Mary Burns, Engels' long-time companion, left Manchester, England to join Engels in Brussels. In mid-July 1845,