Tisha b’Av, the ninth day of the Hebrew month of Av, begins Wednesday evening, according to the Jewish calendar – which is lunar, and therefore the ‘day’ begins and ends at sunset.

The most famous events that occurred on that infamous day were the destruction of both the first and second Holy Temples in Jerusalem, in 423 BCE and 69 CE, respectively. Since then, Jews have been wandering from place to place and have lived in various countries across the globe.

An earlier event, known mostly by those familiar with biblical text, was the “sin of the spies” in 1313 BCE, not long after the exodus from Egypt. On the eighth day of Av, spies who were sent to scout the Land of Israel reported back that the land was inhabited by giants and could not be conquered – despite the Divine promise that they would indeed succeed. Later that night, on the ninth of Av, the Israelites cried and said they would prefer to return to Egypt rather than be murdered by the Canaanites.

As recounted in the bible, God was angered by this lack of faith and punished that generation, saying only their children would merit to enter the Promised Land – 38 years later.

In 133 CE, on the ninth of Av, the Jews who rebelled against Roman rule, believing that their leader, Simon bar Kochba, would be victorious and usher in the messianic era, were slaughtered in the final battle at Betar, southwest of Jerusalem.

On the same Hebrew date, the Jews were expelled from England in 1290 CE and from Spain in 1492. It also marked the beginning of World War I in 1914, when Germany declared war on Russia, which ultimately led to World War II and the Holocaust.

Finally, Tisha b’Av is the culmination of the “Three Weeks” of mourning observed by religious Jews the world over, beginning with the fast of the 17th day of the month of Tammuz, when the walls surrounding Jerusalem were breached during the First Temple-era. While weddings and other joyous occasions are not held during this period, the restrictions become more intense during the last nine days, during which Orthodox Jews refrain from eating meat (except for on the Sabbath) and from wearing new clothing.

On the fast day of Tisha b’Av, the Book of Lamentations is recited at synagogue, and congregants sit on low stools.

Legend has it that Napolean, upon observing Jews crying on Tisha b’Av and learning the reason why, said that “a nation that cries and fasts for over 2,000 years for their land and Temple will surely be rewarded with their Temple.”

According to Jewish tradition, Tisha b’Av will become a day of celebration after the arrival of the Messiah.