Ludo Martens was a Belgian historian noted for his work on francophone Africa and the Soviet Union. He was also the chairman of the Workers' Party of Belgium.
In 1968 he founded the Maoist group "Alle macht aan de arbeiders" (All Power to the Workers), which in 1979 became the Workers' Party of Belgium.
Martens wrote on the political history of the Democratic Republic of the Congo, where he has lived and traveled extensively.
In 1994, Martens published Another View of Stalin, a history of the Soviet Union under Stalin that challenges in particular the dominant view of collectivization in the USSR and the Great Purge. He explained his motivation for writing the book in the introduction: "Defending Stalin's work, essentially defending Marxism-Leninism, is an important, urgent task in preparing ourselves for class struggle under the New World Order."
Martens wrote primarily in French; however, his books, especially Another View of Stalin, have been translated into Dutch, English, and numerous other languages. He was a leading Marxist theorist within the anti-revisionist movement, and is therefore perceived as a "Stalin apologist".
Within the International Communist Movement, he is noted for having proposed the unification of the four main tendencies of the Marxist-Leninist movement. These are the pro-Soviet groups, the pro-Chinese, the pro-Albanian, and pro-Cuban. In addition there are "independents." Martens has put forward that while at a certain time these separations were important and based on principle, they can now be overcome and the movement can be united on the basis of Marxism-Leninism. In order to develop this unification process, the Workers Party of Belgium hosts the International Communist Seminar in Brussels, which is attended by 150 organizations around the world.