In April 1940, the Judenrat was ordered to construct walls to prevent the movement of Jews into "Aryan" neighborhoods. After a few SS attempts to establish a Ghetto in the city, a decision was reached in the fall of that year, to confine the Jews in a Ghetto.
On Yom Kippur, October 12th, 1940, the decision to establish a Ghetto was announced. According to German data, 113,000 Poles were removed from the area marked for the Ghetto, and 138,000 Jews, from all over the city, were transferred to the site.

On November 16th, the Ghetto in the Jewish neighborhood in the northern part of the city was sealed off. Thirty percent of the population of the city was squeezed into an area the size of 2.4% of the total city land mass. German statistics report six to seven people per room.
In an area comprising 73 city streets, 450,000 people lived during the period of greatest population concentration in the Ghetto. Some of the residents had been transported from other parts of Poland, and later, people arrived from the Reich territories. With the move to the Ghetto, many lost their livelihoods. Survival depended on finding some way to make a living inside the Ghetto. About 9,000 Jews who worked in the "platzovki" [placowki - crews accompanied by guards] went out to the "Aryan" side to work.
In 1941, living conditions in the Ghetto became even more unbearable. Official German food allocations were set at 184 calories a day per person and the Judenrat, (the Jewish Council, the official leadership), under Adam Czerniakow, failed to meet both the needs of the Jews and the demands of the Germans.
An intricate system of smuggling arose in the Ghetto. Organized Jewish underworld criminal gangs, working hand in hand with Poles, smuggled food and raw materials for underground industries into the Ghetto and also smuggled finished goods out to the "Aryan" side. At the same time, independent smugglers, mainly women, and children managed to bring in food for their starving families. The Germans used all the means at their disposal to combat the smuggling activity especially because smuggling entailed leaving the Ghetto and necessitated contact between Jews and Poles, who, despite their "racial inferiority" (in the opinion of the Germans), still belonged to the "Aryan" race. Starting in November 1941, Jews caught outside of the Ghetto were executed. As part of the campaign against smuggling, the Germans decreed that buildings found to be used by smugglers would no longer be part of the Ghetto. Fences, later replaced by walls, were erected even in the middle of streets.

The Ghetto, crowded as it was, was made even smaller.
In the winter of 1941, the situation became even more desperate as typhus epidemics caused many deaths. Until the summer of 1942, there was no systematic German policy regarding the murder of Jews. In essence, the German program was an assault on human dignity, aimed at humiliating and debasing the Jews. In light of this, the help people gave each other, and the struggle to maintain humane relationships in the Ghetto was remarkable. Public figures and Jewish businessmen representing the entire range of political affiliations joined together to form the Jewish Mutual Aid Society, and in addition to welfare projects, they founded soup kitchens, developed a network of Building Committees, organized cultural affairs, and strove desperately to alleviate the hunger of thousands of starving children in the Ghetto. These activities and the determination of many to lead Jewish lives reflect the struggle to preserve fundamental human values while fighting for survival.
On July 22, 1942, the Great Deportation [Aktzia] began in the Ghetto. [Aktzia Action; the term used for the deportation to the death camps]. In the four escalating stages of the deportation, approximately 265,000 Jews were sent to the death camp at Treblinka. About 50,000 received "life numbers" - official permission to live and work to support the German military effort. Another 10,000 "wild" Jews (without this German permit) managed to survive the Great Deportation. These survivors were concentrated in an area known as the Main Ghetto, around the German factories in which they worked.
On January 18, 1943, the Germans initiated the second stage of the deportation, designed to dilute the Jewish population in the remaining Ghetto area. This provoked the first Jewish armed insurgency against the Nazis, carried out by members of the Jewish Fighting Organization.
On April 19th, 1943, Passover Seder night, the final deportation began and served as the spark that ignited the Warsaw Ghetto Uprising. The new Uprising was unique because all the Ghetto Jews were involved this time, in contrast to the few who took part in the "small" uprising on January 18, 1943. The Jews believed that the Germans had retreated because of the JFOs uprising. The fighting organization became the informal leadership of the Ghetto from that moment on. They worked during the day and at night, fortified bunkers in preparation for the end of the Ghetto.
The JFO learned how to fight: don't meet the well-armed and well-trained Germans face-to-face. Between the two uprisings, the JFO and the Jewish Military Organization [Zydowski Zwiazek Wojskowy - ZZW] divided the Ghetto into military sectors.

As the Germans entered the Ghetto they were attacked they were ambushed by the Jewish fighters. Leading the revolt was Mordechai Anielewicz, a member of the Hashomer Hatzair Zionist Youth Movement. The Germans suffered 58 casualties and were forced to withdraw. SS Brigadefuhrer Jurgen Stroop replaced the German commander. He decided to fight the resistance by burning down the ghetto building by building. The resistance fighters were often located in bunkers that would have to be captured one at a time. The Germans had hoped to liquidate the remainder of the ghettos in three days; instead, they spent almost a month conquering it against opponents who were often armed with no more than a pistol.

On May 8th the Germans found the headquarters of the Jewish resistance at 18 Mila Street. The leaders of the revolt including Mordechai Anielewicz committed suicide instead of taking a chance of being captured.

 

In the Ghetto's last months, 20,000 Jews found shelter on the Polish side of the city. Many were assisted by members of the Polish Underground movement, who formed the Council to Aid the Jews, known under its codename Zegota, The few thousand Jews who did not perish in the flames that devoured the Ghetto, or were not murdered during the German attempts to crush the Uprising, were sent to the Maidanek [Majdanek] concentration camp, or to various other work camps.
As a symbol of the suppression of the Uprising and the German victory over the insurgent Jews, the SS General Jurgen Stroop ordered the destruction of the Great Synagogue on Tlomacka St. on May 16th, 1943, and in his report he wrote, "the Warsaw Ghetto is no more.”

In total 16 German soldiers were killed and 300 wounded in the military action to put down the revolt. The significance of the uprising was not in the numbers, however. All those in the Ghetto when the rebellion began were slated to killed at Treblinka, instead of being killed quietly, those who organized the revolt showed that Jews could and would fight back.