Josef Kaplan and Halina Semadar walking in the streets of Warsaw.

Josef Kaplan and Halina Semadar walking in the streets of Warsaw.

Josef Kaplan (1913-1942), was a leader of the Hashomer Hatzair socialist Zionist youth movement in interwar Poland. During the Nazi occupation he took charge of the movement's underground organization and coordinated its activities in the various ghettos. In the summer of 1942 Kaplan helped found the ZOB [Jewish Fighting Organization] in Warsaw. Two months later, however, on September 3, 1942, he was captured and killed by the Germans while preparing forged documents for members of the underground, who were about to escape to the forests to join the partisans.