The diplomat Jan Karski was drafted into the Polish army after the German invasion of Poland, and was soon captured as a prisoner of war. He escaped in December 1939 and joined the Polish Underground State (Polskie Państwo Podziemne) in Warsaw. He ran courier services between the organization and the Polish government-in-exile in London.
In 1942 Karski was smuggled into the Warsaw ghetto and a transit camp in Izbica, in order to document crimes against Jews in Poland. He observed the inmates’ deportations, then went to London to inform the government-in-exile and the British authorities. The Polish government-in-exile composed a diplomatic note to the Allies on the basis of Karski’s observations. In 1943 he went to the United States, where he asked President Franklin D. Roosevelt to undertake measures against the crimes. However, the Allies paid little attention to Karski’s information and appeals. In 1944 he published a book about his experiences in occupied Poland to inform the general public.
After the war, Karski refused to return to communist Poland. He was honored as Righteous Among the Nations in 1982.