Tisha B'Av

Tisha B’Av literally means the "ninth day of the month of Av."  It is the major day of communal mourning in the Jewish calendar. You may have heard that many Jewish holidays have the same theme: "they tried to kill us, we survived, let's eat!" Tisha B'Av is all about that first part, "they tried to kill us."

Short answer: everything bad that has happened to the Jews! 

The rabbis believe that G!d ordained this day as a day of disaster as punishment for the lack of faith evidenced by the Israelites during their desert wanderings after the exodus from Egypt. The most notable event we remember is the destruction of the first and second temples in Jerusalem, which are both said to have been destroyed on Tisha B'Av. 

• The Twelve Spies sent by Moses to observe the land of Canaan returned from their mission. Only two of the spies, Joshua and Caleb, brought a positive report, while the others spoke disparagingly about the land. The majority report caused the Children of Israel to cry, panic and despair of ever entering the "Promised Land". For this, they were punished by G!d that their generation would not enter the land.

• The First Temple built by King Solomon was destroyed by Nebuchadnezzar in 586 BCE, and the population of the Kingdom of Judah was sent into the Babylonian exile.

• The Second Temple built by Ezra and Nehemiah was destroyed by the Romans in 70 CE, scattering the people of Judea and commencing the Jewish exile from the Holy Land, which would last until 1948.

• The Romans subsequently crushed Bar Kokhba's revolt and destroyed the city of Betar, killing over 500,000 Jewish civilians (approximately 580,000) on August 4, 135 CE.

• Following the Bar Kokhba revolt, Roman commander Quintus Tineius Rufusplowed the site of the Temple in Jerusalem and the surrounding area, in 135 CE.

• The First Crusade officially commenced on August 15, 1096, killing 10,000 Jewsin its first month and destroying Jewish communities in France and the Rhineland.

• The Jews were expelled from England on July 18, 1290.

• The Jews were expelled from France on July 22, 1308.

• The Jews were expelled from Spain on July 31, 1492. 

• Germany entered World War I on August 1–2, 1914 which caused massive upheaval in European Jewry and whose aftermath led to the Holocaust.

• On August 2, 1941, SS commander Heinrich Himmler formally received approval from the Nazi Party for "The Final Solution." As a result, the Holocaust began during which almost one third of the world's Jewish population perished.

• On July 23, 1942, began the mass deportation of Jews from the Warsaw Ghetto, en route to Treblinka.

• The AMIA bombing, of the Jewish community center in Buenos Aires, killed 85 and injured 300 on July 18, 1994.

For approximately 24 hours (adding on as is usual with Jewish sacred time), Jews act out total grief on Tisha B’Av. The symbolic acts draw from the rituals of a mourner sitting shiva, but the powerful paradigm is that of an overwhelmed defender of Jerusalem, now a Roman prisoner of war. From sundown to sundown, traditional Jews neither eat nor drink nor wash nor anoint themselves (recall the scenes of Jews in the Holocaust, kept sitting in the open squares all day without food or water). In the same spirit, they give up sexual relations that night. The story of the destruction is retold vividly by reading the Book of Lamentations. Unshaven, unwashed, hungry, people re-experience the tragedy of the Destruction.

Source: https://www.myjewishlearning.com/article/a-communal-mourning/ 

https://www.chabad.org/library/article_cdo/aid/144575/jewish/What-Is-Tisha-BAv.htm 

https://www.jewishvirtuallibrary.org/tisha-b-av 

https://www.myjewishlearning.com/article/tisha-bav-101/ 

https://www.myjewishlearning.com/article/a-communal-mourning/ 

https://www.myjewishlearning.com/article/tisha-bav-rituals-practices/ 

https://reformjudaism.org/jewish-holidays/tishah-bav