Tisha B'Av is the saddest and tragic day of the whole year, is the fast of the Ninth of Av, it is a day of fasting and morning the destruction of the first Temple in 586 B.C.E and also the destruction of the second Temple in 70 C.E, the first Temple was ransacked by the Babylonians and burnt to the ground, the second Temple by the Romans, the destruction however was not only a religious disaster, but it was also the end of the first and second Jewish Commonwealth and with this the exile of most of the Jewish people from their very own land. Tisha B' Av became indentified with yet another tragic event in the lives of Jewish people in Spain, in 1492 they issued a decree, the expulsion of all Jews and the only alternative was death or conversion to Christianity.
At first, the destruction of the Temple is the basic reason of the mourning of Tisha B'Av, as the Temple is still not restored. In the year 691 C.E Islamic leaders built a major Islamic shrine on the Holy Temple Mount and this only highlights the Temple's loss to the faith of Israel.
Secondly, there is another occasion each year to remember and never to forget, to mourn and grieve over all those occasions in history of Israel, which resulted in sorrow, suffering and in death, in torture, cruelty and oppression, which did reach their climax in the Holocaust of 1940- '45, where a third of all Jewish people, men, women and children, were systematically and in a extremely gruesome way put to death after the most horrific suffering.
Tisha B' Av is a day of total fasting as on Yom Kippur, are there certain things forbidden before sundown the eights of Av till nightfall the fallowing day, there are restrictions against studying Torah.
Tisha B'Av marks the height of a period of three weeks, this is to be observed in semi- mourning, and begins with the minor fast of the 17th of Tammuz, this marks the the first breach in the Walls of Jerusalem, made by the attacking of the babylonians.
During the three weeks of mourning, weddings are not permitted or any other celebrations where there is music involved. The semi- mourning intensifies on the first day of Av, the period reffering to as the Nine days. At this time it is custom not to eat meat or drink wine during this period, except on Shabbat. Buying new clothing has to wait until after Tisha B'Av.
On the fallowing evening service, the Meggillat Eichah, this is the Book of Lamentations,is read in a more mournful way, this is in the evening as well as in the morning. Kinot chanted after the Eichah are recited sitting on the ground or on a low stool and Tallit or Tefillin are not been worn, also on the day itselves the parokhet is removed for less decorative cover and in some communities they even drape the Ark in black.