Salomon Hakker was a son of André Hakker and Rebecca Schuijer. He married Grietje Porets 25 May 1904 in Den Haag, a daughter of Isaac Porets and Maria Wilkins. The couple had four daughters of whom two have survived the war. Their daughters Maria and Esther however have been killed in the Shoah.
Municipal Archive of Den Haag, certificate of marriage nr. 678-1904 of Salomon Hakker and Grietje Porets and the family registgration card of Salomon Hakker of the People’s Registry of Den Haag.