Simon van der Horst was a son onf Karel van der Horst and Reintje Turksma. He married 1 August 1923 in Amsterdam to Clara van der Ven, a daughter of Simon van der Ven and Branca Polak. The couple had two children: Branca and Karel.
Simon was born in a family with seven children, of whom three children have survived the war. His other siblings, Meijer, Alida and Izaak have been killed during the Ho…