Karl Marx (1818-1883) was Prussian-born philosopher, economist, political theorist, sociologist, journalist, and revolutionary socialist. His collaborated with Friedrich Engels in writing The Communist Manifesto (1848). Expelled from Prussia in the same year, Marx took up residence first in Paris and then in London where, in 1867, he published his magnum opus Capital.

Friedrich Engels (1820-1895) moved to England in 1842 to work in his father's Manchester textile firm. After joining the fight against the counter revolution in Germany in 1848 he returned to Manchester and the family business. In subsequent years he provided financial support for Marx and edited the second and third volumes of Capital. He is the author of The Condition of the Working Class in England (1845), and co-author, with Karl Marx, of The Communist Manifesto (1848).