Karel Biedermann was a son of Maijer Markus Biedermann and Justine Kann. He married 29 January 1915 in Zaandam to Esther Englander, a daughter of Nathan Englander and Lea Rimini. The couple had one daughter: Justina.
Karel self had another brother and three sisters: Isaac, Thérèse, Bertha and Regina. They too have been killed in the Shoah.
City Archive of Amsterdam, archive card of Karel Biederman…