Isaak de Wolf was a son from the first marriage of his father Jacob de Wolf and Rebecca Blog, who passed away in 1932. He married Frederika Springer in Amsterdam on 24 May 1939; she has survived the Holocaust. The couple had no children. Isaak has been killed already on 10 August 1941 in Mauthausen. The family lived at Nieuwe Uilenburgerstraat 36 II in Amsterdam.
Isaak was born into a family of seven children. Two little brothers have died already, only 2 years old. The other family has been killed in the Shoah: His father Jacob, together with his wife Heintje Roeg were killed in Auschwitz; his brother Samuel was also killed in 1941 in Mauthausen; his brothers Gerrit and Willem were killed in 1943 in Sobibor an his brother Mozes in 1943 in Auschwitz.
City Archive of Amsterdam, archive cards of Jacob de Wolf, Gerrit de Wolf, Willem de Wolf, Samuel de Wolf, Mozes de Wolf, and Isaac de Wolf and an addition of a visitor of the website.