In 1938, Albert and Roger sent their wives to Vichy because of the threat of war with Germany. After the German invasion, Albert Lang and his wife moved to Brive la Gaillarde in Corrèze. The very young Jack and his mother went to stay with his great grandmother (the mother of Berthe Boulanger) in Cholet and subsequently moved to Bordeaux. His father Roger was first mobilized in Luneville, and then joined his parents and his brother-in-law Luc Bouchet in Brive. Jack and his mother also joined them in Brive after the bombing of Bordeaux. Jack Lang's father was sentenced by the court in Brive for failure to report his children as Jews, but was later acquitted by the Court of Appeal on the ground that the children's mother was a Catholic. He had followed the advice of the rabbi of Brive, David Feuerwerker.