Jakob Polak from Wildervank was a son of Nathan Isaak Polak and Rachel Cohen. He married 14 March 1928 in Rotterdam Henriette Helena Polak, a daughter of Michel Polak and Klaartje van Gelder. As far as known, this couple had no children.
Since 26 March 1930, his unmarried sister Betje lived in with Jakob and his wife Henriette, first at Virulyplain 3b and per 26 March 1938 at Doezastraat 32 b in Rotterdam. It is unknown when Jakob, his wife and sister were deported to Westerbork. However, 12 October 1942 they were put on transport to Auschwitz and on arrival there, 15 October 1942, immediatelty killed.
City Archive of Rotterdam, family registration cards of Jakob Polak and Betje Polak; website wiewaswie, wedding of Jakob Polak/Henriette Polak and the file cabinet of the Jewish Council, registration cards of Jakob Polak, Henriette Helena Polak-Polak and Betje Polak.