Joseph de Rooij, a butcher by trade, was a son of Mozes de Rooij and Elizabeth Moscoviter. On 10 February1937 he married in Rotterdam Leentje Boeki, a daugther of Azor Boeki and Hendrika Kulman. In 1942, the couple had a son Mozes Henny.
Joseph de Rooij lived with his wife Leentje Boeki in April 194…