Imam Hossein , third Imam of Shia Muslims , grandson of Mohammad (Islam's prophet) And his family beside seventy two of the best people of that age were martyred in Karbala (in Iraq).
We as shia Muslims mourn every year, the first ten days of Moharram (first month of new year of Hijri Qamari). This is not something as a tradition but a spiritual lamentation.
Unfortunately some extremists that their deeds are not wise according to every rational Shia ,do mourning in irrational ways such as , cutting themeselves, wearing dog's collar or reading poems that despise the dignity of human being, etc.
Shia enemies misuse of these irrational mournings that are done by some minorities, to spoil Shias. So dear Shias careful about your holy mournings.There is a picture of mourning , an irrational one,somewhere in Afghanistan, unfortunately…