In 1940, he served with the
French Army. In 1940,
Northern Transylvania was transferred under the
Second Vienna Award from Romania to Hungary, and as such his parents and siblings came under Hungarian rule. A member of the
French Resistance, he was given charge of the
FTP-MOI's south-western region. He began his resistance career in Lyons and later moved to Toulouse. He adopted as his alias Gaston Marin, which after the war he took as his surname. Finally, he moved to work with the miners of Carmaux, long famous in France for their militancy. In July 1944 he instigated the revolt at the
Tarn mines, one of the first steps in the French liberation from
German occupation. In August 1944, Gaston liberated the French city of
Carmaux, capturing 120 German soldiers. A few days later, he also liberated
Albi, the capital of the Tarn region. Upon his return to Romania, he learned that in 1944 his entire family had been deported by the Hungarian authorities to
Auschwitz, where all of them had been exterminated. ==In Communist Romania==