He took up studies at the "United State Schools for Fine and Applied Art", (Vereinigte Staatsschulen für Freie und Angewandte Kunst) in Charlottenburg with Wilhelm Gerstel (1879–1963), whose master student he became from 1934 to 1938.

During a trip to London in 1937, Cremer met the writer and playwright Bertolt Brecht, the composer Hans Eisler and the actor Helene Weigel there,[12] who advised him to continue working in Germany.

He was in close contact with the Red Orchestra resistance group around the sculptor Kurt Schumacher and the writer Walter Küchenmeister.

[citation needed] From 1940 to 1944, he served in the Wehrmacht as an anti-aircraft soldier in Eleusis and on the island of Crete,[15] after which Cremer became a prisoner of war in Yugoslavia.

In October 1946, vouched for by his party comrades, he was awarded a professorship and the chair of sculpture department of the Academy for Applied Art in Vienna.

Controversy was sparked off by the memorial's dedication to the victims of Fascism as from 1934, the year that an authoritarian regime accepted by the Catholic Church took power in Austria.

[4] His most important work by far during his earlier life in the GDR is his 1958 bronze sculpture "Revolt of the Prisoners" (Revolte der Gefangenen); set in front of a bell tower, high up in the hills above Weimar, the grouping of 11 figures, some gesturing triumphantly, forms the focal point of a memorial at the site of the former concentration camp of Buchenwald.

[24][25] Cremer was respected in the GDR because he sometimes spoke up against the communist regime's stubborn denial of modernism and artistic liberty; he was never censored since no doubt seems ever to have been cast on his political sincerity.

Part of his authority, of course, was due to his decision to move to the East and to denounce Western policies during the Cold War.

A good example of his intransigency, comparable to that of the right-wing caricaturist Andreas Paul Weber in West Germany, was the widely distributed and quite masterly cycle of lithographs in which he denounced the Hungarian rebellion, shortly after the event.