Willie Muzenberg was born in Germany in 1889. Muzenberg became interested in social problems and at the age of seventeen joined the Social Democratic Party. Soon afterwards he moved to Switzerland where he came into contact with exiled revolutionary groups such as the Bolsheviks. He met Vladimir Lenin and after that became his devoted follower. Muzenberg was eventually arrested and deported from Switzerland for being an undesirable foreigner.

Muzenberg opposed the First World War joined with a group of radicals that survived the failed German Revolution to form the German Communist Party (KPD).

The party's first congress was addressed by Gregory Zinoviev, the Russian Bolshevik and head of the Comintern. Throughout the 1920s Muzenberg and the KPD was very much under the influence of Communist Party of the Soviet Union.

In 1921 Muzenberg founded the International Worker's Relief in Germany, an organization that raised money for people in Russia suffering from the great famine.

Muzenberg became one of the leaders of the KPD, now the largest Communist Party outside the Soviet Union and was fairly successful in elections to the Reichstag: 62 (May, 1924), 45 (December, 1924), 54 (May, 1928), 77 (September, 1930), 89 (July, 1932) and 100 (November, 1932).

After the Reichstag Fire on 27th February, 1933, Hermann Goering and the Nazi Party launched a wave of violence against members of the German Communist Party and other left-wing opponents of the regime. Some of the party's leaders such as Ernst Thalmann were arrested but Muzenberg managed to escape and went to live in France

Muzenberg broke with the Soviet Union as a result of the signing of the Nazi-Soviet Pact and now became an outspoken critic of Joseph Stalin. After the invasion of France by the German Army Muzenberg was interned in Lyon as an anti-fascist. Willie Muzenberg was murdered by agents of the NKVD in 1940.