Maurice Joost Son was a son of Mozes Joseph Son and Hermine Fischer. He married 30 August 1933 in Rotterdam Edith Hirsch from Linz, a daughter of Heribert Hirsch and Sophie Gottschalk. The couple had two children, Anita Jos and Joost Maurice Jos.
After the passing of his mother Hermine Fischer on 22 May 1940 in Rotterdam, the family moved to Amsterdam, Amstelkade 167 on 21 September 1940.
Edith Hirsch and her son Joost Maurice Jos have survived the Holocaust. Maurice Joost and his daughter Anita Jos however were killed during the Shoah. Also his brother Alouis Herman was killed during the Shoah.
City Archive of Rotterdam, family registration cards of Joseph Mozes Son, Maurice Joost Son and website www.wiewaswie.nl.