It was on the night of the 9th of Av that the spies in the Wilderness brought back a negative report on the Land and caused us to wander for 40 years in the Wilderness , for they caused the people to cry and mourn in their tents for no reason and so , HaShem Ordained that on that day , the 9th of Av , Tisha B'Av , we would have reason to mourn through the centuries and so , today we Fast on Tisha B'Av . So many calamities happened to our people through history on and around this day : - Both our Holy Temples were destroyed with the conflagration carrying on into the next day . The City of Betar was destroyed by the Romans . Jerusalem was attacked . It was on this date that the Jews had to leave Spain after centuries of living there when 529 years ago , by royal edict the expulsion of Jews took place under Queen Isabella and Duke Ferdinand . It was on this date that Boghdan Chmielnitsky and his Ukrainian Cossacks ran through the Ukraine and Poland killing thousands of Jews and raping and pillaging . It was on this date that the Final Solution was signed for the destruction of Jews in the Holocaust by Nazi Germany. It was on this date that the crusaders went through Europe and England decimating many Jewish villages and burning our holy scrolls and killing many of our people . It was on this date that Russian Cossacks attacked many villages of Jews in Russia. It was on this date that so many other things happened to us through history. May our people finally learn that it is only HaShem that w must follow and only HaShem's Torah Laws that we must obey . Wishing all my fellow Jews a Meaningful Fast. May HaShem Come Soon In Our Days .