Engels

Carver, Terrell.
New York : Hill and Wang, 1981.

Karl Marx : an intellectual biography

Hosfeld, Rolf, author.
New York : Berghahn Books, [2013]
English-language ed.

Karl Marx and the birth of modern society : the life of Marx and the development of his work

Heinrich, Michael, 1957- author.
New York : Monthly Review Press, [2019]-

Karl Marx : the story of his life

Mehring, Franz, 1846-1919.
London : Routledge, 2010.

The last revolutionaries : German communists and their century

Epstein, Catherine.
Cambridge, MA : Harvard University Press, 2003.

Marx, life and works

Rubel, Maximilien.
New York, N.Y. : Facts On File, Inc., 1980.

Marxism in a lost century : a biography of Paul Mattick

Roth, Gary, author.
Leiden ; Boston : Brill, [2015]

The red millionaire : a political biography of Willi Münzenberg, Moscow's secret propaganda tsar in

McMeekin, Sean, 1974-
New Haven : Yale University Press, [2003]