Ashura is the day when Imam Hussain was martyred at the Battle of Karbala. Imam Hussain is the Grandson of Prophet Mohammad and the Son of Imam Ali. Due to very acute sufferings and tragedies befall on Imam Hussain, shiites offer him their tribute for his selfless sacrifice to save humanity and Islam.
Shiites shows their love and tribute by doing mourning rituals (Azadaari) with devotion.
Matam is a form of mourning that involves chest-beating or self-flagellation, this could be of 2 types: Qamazani, hitting swords on heads and Zanjeerzani, hitting back with knives.
Lucknow, Uttar Pradesh, India. November 2014.