Our Wise men established we are in mourning every year from 17 Tamouz to 9 Av. We then commemorate the loss of Beth-Hamikdach. It’s on a 17 Tamouz that the Romans pulled down the outer wall of the city before the Temple was destroyed on 9 Av.
During that period, the Jewish people went through a lot of suffering and pogroms multiplied, «Pogrom» is a Russian’s word which means «destroy», «plunder». Cossacks committed many progroms to massacre hundreds of thousands of Jews.
From the destruction of the first Temple of Jerusalemn until today, tragic events have affected the Jewish people. Bloody and hateful people without any morality in Europe or in the Eastern world have killed, burnt and moved Jews away from their homes , without reason, just out of pure hated and jealousy.