Jacob Cohen de Heer, born 1912 in Rotterdam, was a son of Jacob Cohen de Heer from Dordrecht and Alida Betsi van Witsen. 6 April 1938 he married Sientje van der Sluijs in Rotterdam, a daughter of Marcus van de Sluijs and Schoontje van der Sluis. 6 March 1939 the couple had a son, who was named Jacob too.
Jacob Cohen de Heer was an office- and bank clerk. In 1932 he lived for half a year with his g…