Edgar Marcel Longuet (18 August 1879[1] – 12 December 1950), was a French physician and socialist activist, and a grandson of Karl Marx.
[4] He was active in the French labor movement and in 1905 joined the Socialist Party, being a supporter of Jules Guesde.
[6] In 1948, Longuet donated a daguerreotype to the Institute for Marxism-Leninism at the Central Committee of the CPSU in Moscow that depicted his grandfather Karl Marx with daughters Jenny (Longuet's mother), Eleanor and Laura and family friend Friedrich Engels.
[7] In the same year he took part in the celebration of the 100th anniversary of the Communist Manifesto in the Soviet Union and in People's Republic of Poland which his grandfather Karl Marx and Friedrich Engels had written.
His brother Jean was also an active socialist, and a member of the French Chamber of Deputies.