Shortly after the German invasion of Poland in September 1939, more than 400,000 Jews in Warsaw, the capital city, were confined to an area of the city that was little more than 1 square mile.

In November 1940, this Jewish ghetto was sealed off by brick walls, barbed wire and armed guards, and anyone caught leaving was shot on sight. The Nazis controlled the amount of food that was brought into the ghetto, and disease and starvation killed thousands each month.

Similar Jewish ghettos were established in cities throughout Nazi-occupied Eastern Europe during World War II. The Warsaw ghetto was the largest in Poland.

In July 1942, Heinrich Himmler, the head of the Nazi paramilitary corps known as the Shutzstaffel (SS), ordered that Jews be “resettled” to extermination camps. The Jews were told they were being transported to work camps; however, word soon reached the ghetto that deportation to the camps meant death.

Two months later, some 265,000 Jews had been deported from the Warsaw ghetto to the Treblinka extermination camp, while more than 20,000 others were sent to a forced-labor camp or killed during the deportation process.

An estimated 55,000 to 60,000 Jews remained in the Warsaw ghetto, and small groups of these survivors formed underground self-defense units such as the Jewish Combat Organization, or ZOB, which managed to smuggle in a limited supply of weapons from anti-Nazi Poles, and the Jewish Military Union.

On January 18, 1943, when the Nazis entered the ghetto to prepare a group for transfer to a camp, a ZOB unit ambushed them. Fighting lasted for several days before the Germans withdrew. Afterward, the Nazis suspended deportations from the Warsaw ghetto for the next few months.

On April 19, 1943, Himmler sent in SS forces and their collaborators with tanks and heavy artillery to liquidate the Warsaw ghetto.

Several hundred resistance fighters, armed with a small cache of weapons, managed to fight the Germans, who far outnumbered them in terms of manpower and weapons, for nearly a month.

However, during that time, the Germans systematically razed the ghetto buildings, block by block, destroying the bunkers where many residents had been hiding. In the process, the Germans killed or captured thousands of Jews.

By May 16, the ghetto was firmly under Nazi control, and on that day, in a symbolic act, the Germans blew up Warsaw’s Great Synagogue.

An estimated 7,000 Jews perished during the Warsaw ghetto uprising, while nearly 50,000 others who survived were sent to extermination or labor camps. It’s believed that the Germans lost several hundred men in the uprising.