Sander Leendert van Gelder was a son of Leendert Joseph van Gelder and Henderina van Vriesland. He marride Debora Halmans on 3 November 1910 in Amsterdam, a daughter of David Halmans and Sophia de Jongh. Their son Leo did not survive the Holocaust too.
Sander Leendert van Gelder was born in a family with ten children; one brother died young, eight years old in 1888; most likely, three of his brot…