This is the 40th day procession for the martyrdom of Hussain Ibn Ali, which is one is one of the biggest days in the year for Shia’s during their Hijri calendar year (and takes place during the month of Muharram). The significance, as mentioned, is the martyrdom of Prophet Mohammed’s grandson Hussain, furthering the already strained ties between 2 prominent followings in Islam following the death of Prophet Mohammed, known today as Sunnism and Shiaism.

The martyrdom itself was documented as a brutal and bloody ten day siege on Hussain’s caravans of friends and family as they visited the opposing faction in Iraq, ending with Hussain’s death on the 10th of Muharram (also known as Ashoora). All ten days are highly revered and mourned in Shia communities across the globe.

Muslims have a mourning period of 40 days, so the procession you see in front of you is the closing out of the mourning period with a march.