Bernard Koopman was a son of Joel Koopman and Dientje de Vries, both from Leeuwarden, who were married in Amsterdam on 20 August 1885. Bernard was the youngest son of a twin; his twinbrother was David who became an upholsterer and who was unmarried. Bernard, also an upholsterer, married Sara Saphier in Amsterdam on 9 March 1919, a daughter of Marcus Saphier and Sophie Hillesheim. The couple had n…