Jacob Blok was a son of David Hartog Blok and Betje de Leeuw. He married as a 27 year old 2nd Lieutenant on 4 February in Den Haag Mietje Zon, a daughter of Abraham Jacob Zon and Henriette Cohen. The couple had a son, Alfred David Henri who was born in Batavia (Dutch Indies). The marriage ended by divorce which was registered in the Civil Registry of Den Haag on 6 March 1902. On 2 December 1903 Ja…