Izak Marcus was the son of Nathan Marcus and Judith Meijer. He was the brother of Betje.
In November 1942 he was transported to Westerbork together with other Jewish residents of Zaltommel.
C. Frankenhuis-van Scheijen en E.E. Können, De vier joodse begraafplaatsen van Zaltbommel (Zaltbommel 1994)
In addition, a Jokos file (number 7252) on this household is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.
A memorial in Zaltbommel commemorates the Jewish victims of this town. More information on this memorial can be found (in Dutch) on the website of the Nationaal Comité 4 en 5 mei.