Israel Shahak was born Israel Himmelstaub, in 1933, in Warsaw, Poland, and was the youngest child of a cultured, Zionist family of Ashkenazi Jews. During the Second World War, the Nazi occupation of Poland (1939–1945) interned the Shahak family to the Warsaw Ghetto; yet his elder brother escaped from Poland to the United Kingdom, where he joined the Royal Air Force. Meanwhile, life in occupied Poland forced Shahak's mother to pay a Roman Catholic family to hide Israel, whom they returned when she could not afford their safe-keeping him from the Nazis.