Maksymilian Horwitz was a leader and theoretician of the Polish communist movement.

He was a member of the Polish Socialist Party - Left

Polish Socialist Party - Left

Polish Socialist Party – Left also known as Young Faction was one of two factions into which Polish Socialist Party divided itself in 1906...

 (PPS-Lewica) from 1906 and the Communist Party of Poland

Communist Party of Poland

The Communist Party of Poland is a historical communist party in Poland. It was a result of the fusion of Social Democracy of the Kingdom of Poland and Lithuania and the Polish Socialist Party-Left in the Communist Workers Party of Poland .-1918-1921:The KPRP was founded on 16 December 1918 as...

 (KPP) from 1918 and sat on its Central Committee (1918-20, 1923-24) and politburo (1923-24). Starting from 1921 he was a senior officer of the Communist International, working in Spain, Belgium and Greece. He was arrested by the NKVD

NKVD

The People's Commissariat for Internal Affairs was the public and secret police organization of the Soviet Union that directly executed the rule of power of the Soviets, including political repression, during the era of Joseph Stalin....

 on 22 June 1937 and executed.