Carl Meffert and his sister were born out of wedlock. When their mother died giving birth to a third child, the eleven-year-old Carl was sent to a state care institution where the young inmates had both to attend school and work. From a young age, Meffert learnt to flee threatening situations, and ran away from the home several times. Flight and urgency became the dominant themes of his life. After several unsuccessful attempts to flee the care home, he finally succeeded in 1919. Meffert joined the Spartacus League and was arrested on political grounds one year later. He spent several years in prison, after which he moved to Berlin in the late 1920s to work as a commercial artist. There, he met, among others, Käthe Kollwitz, Erich Mühsam, George Grosz and John Heartfield. During his time in Berlin, he began to explore political and biographical themes in his art. His work from this period includes the linocut series Erwerbslose Jugend [Unemployed Youth] (1928) and Fürsorgeerziehung [Corrective Training] (1928/29).

 In the 1930s, Meffert lived principally in Switzerland. After the burning of the Reichstag in February 1933, he returned to Berlin for a final visit. He narrowly escaped arrest by the Gestapo and managed to flee back to Switzerland. From then on he lived as an illegal immigrant in Switzerland and took the name Clément Moreau. To avoid being arrested by the Swiss immigration police, he fled to Argentina in 1935. There he created the cycle Nacht über Deutschland [Night over Germany] in 1937/38. Even after the end of the Second World War, Moreau’s life as a fugitive continued: when the military junta took power in Argentina in 1962, he visited Switzerland and never returned.