Five disasters happened to the Jewish People in ancient times, on this day:

1. The spies returned with a negative report about the Land of Israel. This report was accepted by the people, who clamoured for a return to Egypt. They were punished with the death of that generation, and a 39-year delay in entering the Land.
   
2. Destruction of First Temple.
   
3. Destruction of Second Temple.
   
4. Jerusalem ploughed over.
   
5. Crushing of rebellion at Beitar. 135 C.E.
   

Other disasters include the expulsion of the Jews from England in 1290 and France in 1390, and from Spain in 1492. Also the First World War broke out in 1914 on Tisha B'Av, in which over half a million Jews were massacred in Eastern Europe. Also, this led directly to the Second World War and the Holocaust.

Therefore, it is a day of national mourning. Here is a brief summary of the laws relating to this Tisha B'Av. Times are for London.

Saturday 28 July: Fast begins at 8.55pm, before the termination of Shabbat.

Shabbat ends at 9.53pm. At this point, one should change into non-leather shoes, and sit on a low chair.

Evening service begins at 10.10pm, and includes the reading of Aycha - Lamentations.

No havdala, but one does say the beracha borei me'orei ha'esh over the candle.

Sunday 29 July: Service begins at 9am. Tallit and Tefillin are not worn.

One sits on the ground - or on a low chair until 1.10pm.

Mincha is at 7.30pm, with Tallit and Tefillin.

Fast ends at 9.45. Havdalah is made, but only with borei peri hagafen and hamavdil.

General: On Tisha B'Av one may only wash hands, up to the knuckles, and wipe the eyes. Also, one should only read 'unhappy' texts, such as Holocaust literature, the book of Job, etc.

If anyone has any specific questions, please feel free to be in touch.