Izak van Blijdenstijn, merchant, was the youngest of the six children of Hijman van Blijdenstijn and Judith Docters, of whom one child was stillborn. Izak was born on 21 October 1894 in Ophemert and married 12 July 1921 in Varik, municipality of West Betuwe, the sister of his brother-in-law Izaäk Kalker, Sophia Elizabeth Kalker. She was a daughter of Mozes Levie Kalker and Rachel Meijer and born o…