Jan Karski was a Polish soldier, resistance-fighter, and diplomat during World War II. He is known for having acted as a courier in 1940–1943 to the Polish government-in-exile and to Poland's Western Allies about the situation in German-occupied Poland. He reported about the state of Poland, its many competing resistance factions, and also about Germany's destruction of the Warsaw Ghetto and its operation of extermination camps on Polish soil that were murdering Jews, Poles, and others.
Emigrating to the United States after the war, Karski completed a doctorate and taught for decades at Georgetown University in international relations and Polish history. He lived in Washington, D.C., to the end of his life. He did not speak publicly about his wartime missions until 1981, when he was invited as a speaker to a conference on the liberation of the camps. Karski was featured in Claude Lanzmann's nine hour film Shoah, about the Holocaust, based on oral interviews with Jewish and Polish survivors. After the fall of the Soviet Union, Karski was honored by the new Polish government, as well as being honored in the US and European nations for his wartime role.