Chaika Grossman was born to a Jewish family in Bialystok, Poland. As a teenager, she joined the socialist Zionist youth group Hashomer Hatzair. In 1939, at the start of World War II, she went to Vilna, Lithuania, to help organize Hashomer refugees fleeing the advancing Nazis. When Vilna also fell to the Nazis, she obtained false identification papers to enable her to travel between the city and the ghettos in Vilna, Lublin, and Warsaw. She made numerous trips across dangerous borders, showing intelligence, courage, and wit when confronted with searches and interrogations by the border guards. Eventually travel became more restricted, and she returned to Bialystok as leader of the ghetto defense there. She and her colleagues bought and smuggled weapons into the ghetto for the Bialystok Ghetto Uprising that began on August 16, 1943 in an effort to stop the mass deportations to the death camps and enable as many Jews as possible to escape into the neighboring Knyszyn Forest. After more than three weeks of intense fighting, she one of the only survivors who escaped alive. She continued her underground activities as the leader of a group of couriers and coordinated resistance activities with partisans in the forest. In 1948, she emigrated to Israel and lived on a kibbutz in the western Galilee. She married Meir Orkin, her childhood friend and counselor in Hashomer, with whom she had two daughters. Eventually, she became a member of the Israeli Knesset (parliament). She was the author of a memoir known in English as The Underground Army: Fighters of the Bialystok Ghetto (1949).