UK the Arbaeen pilgrimage is now in its 35th year
The "Husaini Islamic Trust UK", organizes the procession in UK where thousands of people take part and the organizers decided to condemn terrorism following the recent ISIS attacks in Paris in 2015. Mr Waqar Haider, the organizer, said that the procession failed to gain coverage by the mainstream media because of the "stereotyping". " The Arba'een Pilgrimage is the world's largest public gathering that is held every year in Karbala, Iraq[1][2] at the end of the 40-day mourning period following Ashura, the religious ritual for the commemoration of martyrdom of the grandson of Prophet Mohammad and the third Shia Imam, Husayn ibn Ali's in 680.[3][4] Anticipating Arba'een, or the fortieth day of the martyrdom, the pilgrims make their journey to Karbala on foot,[5] where Husayn and his companions were Martyred and beheaded by the army of Yazid I.[1]

The number of participants in the annual pilgrimage reached 30 million or more by 2016