According to the Mishnah (Taanit 4:6), five specific events occurred on the ninth of Av that warrant fasting:

1.   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 back positive reports, while the others spoke adversely about the land and the people.  It was the others claims about the land and the people that caused the Children of Israel to cry, and to panic about never entering the “Promised Land”.  For this reason, they were punished by G-d that their generation would never enter the “Promised Land”.  It was the Israelites’ lack of faith that G-d  proclaimed that for all generations this date would become one of crying and misfortune for their descendants, the Jewish people.

2.   The First Temple was destroyed by the Babylonians

3.   The Second Temple was destroyed by the Romans, scattering the people of Judea and       commencing the Jewish exile from the Holy Land.

4.   Bar Kokhba’s revolt against Rome failed and Simon Bar Kokhba was killed, and the           city Betar was destroyed.

5.   Following the Roman conquest of Betar, the Romans plowed over the Temple Mount,         our nation’s holiest site.

The Tish’a B’Av fast has 5 main prohibitions:

1. No eating or drinking (even water)

2. No washing or bathing.

3. No appliction of creams or oils.

4. No wearing of leather shoes

5. No martial relations.

These restrictions are suspended in the case of health issues.  Ritual washing up to the knuckles is permitted. Washing to cleanse dirt or mud from one’s body is allowable.

Since this is similar to a shiva, mourning practices of sitting on low stools or on the floor is conducted on the meal immediately before the fast until noon. Torah study is forbidden, except for sad portions like the Book of Lamentations, the Book of Job, portions of Jeremiah and chapters of the Talmud that discuss the laws of mourning.  If possible work is to be avoided.  Old prayerbooks and Torahs are often buried on this day.

When Tish’a B’Av begins on Saturday night, the havdalah ritual at the end of Shabbat is truncated (using a candle but no spices), without a blessing over wine. After Tish’a B’Av ends on Sunday evening, another havdalah is performed with wine (without candle or spices).