Josef Kaplan was born in Kalisz in 1913. When he was at school he joined the Zionist youth movement and by the late 1930s was one of the leaders of the group in Poland.
Kaplan fled east when Poland was invaded by the German Army in September 1939. However, he returned the following year to help organize the resistance against Nazi occupation.
In 1942 Kaplan helped to establish the antifascist coalition in Warsaw. While producing forged documents for a group of resistance fighters on 3rd September 1942, he was captured and killed.
Do not go willingly to your death! Fight for life to the last breath. Greet our murders with teeth and claws, with axe and knife, hydrochloric acid and iron crowbars. Make the enemy pay for blood with blood, for death with death?
Let us fall upon the enemy in time, kill and disarm him. Let us stand up against the criminals and if necessary die like heroes. If we die in this way we are not lost.
Make the enemy pay dearly for your lives! Take revenge for the Jewish centres that have been destroyed and for the Jewish lives that have been extinguished.