On this day in 1943, the Warsaw Ghetto Uprising began. The ghetto, established in November of 1940, was the largest ghetto constructed and controlled by the Nazis during World War II. At the height of its operation, the ghetto held some 460,000 Jews, all of whom were confined to the ghetto as prisoners. German authorities deported and killed roughly 300,000 Jews from the ghetto between July 22 and September 12, 1942. 265,000 Jews were sent to the death camp at Treblinka that summer in what became known as the “Great Action”. While the operation was being carried out, German authorities killed some 35,000 Jews inside the ghetto; by the beginning of 1943, there were only between 70,000 and 80,000 Jews left in the Warsaw Ghetto. Various underground Jewish resistance movements established a unit for armed self-defense, known as the Jewish Combat Organization or, as it was known in Polish, Żydowska Organizacja Bojowa (ŻOB). In addition to the ŻOB, there was also the Revisionist Zionist Movement, a right-wing group which along with Betar, its youth group worked as the central organizers of the Żydowski Związek Wojskowy (Jewish Military Union; ŻZW). While tension remained at the outset between ŻOB and ŻZW, the two eventually formed a strong partnership, rallying around the opposition to German authorities' attempts at destroying the ghetto altogether. When the uprising took place, ŻOB and ŻZW held roughly 500 and 250 fighters within their respective ranks. It wasn’t until October of 1942 that the ŻOB was able to communicate with the Polish military underground movement and acquire small quantities of weapons. Units of the German SS police returned to the ghetto in January 1943, this time carrying the goal of deporting thousands more of the Jews to forced labor camps. The German authorities intended to send these Jews to the Lublin District of the General Government. Following orders brought down by Heinrich Himmler on January 18, German authorities attempted to resume deportations. However, a small portion of Jewish resistance fighters interfered with Jews headed for the transfer point, thus allowing those Jews to break rank and fend off the Germans who served as their escorts. While many of the resistance fighters died, their efforts were successful, sparing those Jews from immediate deportation while sending a message to other Jews of the ghetto to resist further deportation and evade detection by hiding from German authorities. This resulted in fewer than 7,000 Jews being deported and caused the Germans to indefinitely suspend further ones on January 21.These developments motivated Jews “...to construct subterranean bunkers and shelters in preparation for an uprising should the Germans attempt a final deportation of all remaining Jews in the reduced ghetto.” On April 19, 1943, the first night of Passover, the Warsaw Ghetto Uprising began. The ŻOB got hold of early information regarding final deportation and spread the news throughout the ghetto. Jewish resistance forces were outnumbered by almost three-to-one and ultimately lacked training and experience. While their resistance tactics gave the ghetto’s general population an advantage, delaying deportations, forced the Germans to burn the ghetto to the ground. On May 8, 1943, after a month of fighting, German forces took the headquarters of ŻOB. While never known for sure, it is assumed that Mordecai Anielewicz, leader of ŻOB, and much of his commanding staff committed suicide so as to avoid capture. Eight days later on May 16, with the ghetto largely eviscerated, Stroop ordered the Great Synagogue to be destroyed. The German SS would go on to deport some 42,000 ghetto survivors to Poniatowa and Trawniki where there were forced labor camps as well as to the Lublin/Majdanek concentration camp. By November, most of those Jews were murdered in what became known as Operation Harvest Festival, a two-day mass murder operation. A minimum of 7,000 Jews died throughout the uprising while the SS and police captured another 7,000 Jews and sent them to their deaths at Treblinka.