What is Arba'in ?
The Day of Arba'in marks forty days after the Day of Ashura ( the day that Husayn ibn Ali was killed in the Battle of Karbala )
The Arabic word ‘Arba'in’ (pronounced Ar-ba-een) translates to forty (i.e., the fortieth day). In Islamic culture, the traditional period of mourning is forty days. As such, millions of people around the world mark the Day of Arba'in by remembering the story of Husayn, his family, and his companions.
 The Day of Arba'in is the day on which Husayn’s family returned to the land of Karbala to properly bid farewell to the fallen heroes and finally grieve for their loved ones.
After the killing of Husayn and his companions, Yazid’s men took the women and children of Husayn’s family as prisoners. They were degraded as they were forced to walk in chains through many towns and cities including Damascus and Kufa – where they were abused by crowds until they were eventually presented to Yazid and placed in prison.
Hussain may have died, but his movement lived on. His sister Zaynab and son Ali ibn Hussain both gave powerful speeches against Yazid in front of his ministers, calling him out for his corrupt regime and unnerving Yazid’s ministers.  Yazid eventually realised that if he left the family of Husayn at his palace, they would humiliate him in front of his ministers even further and was forced to free them. The family of Husayn would spend their lives after that teaching people about Husayn’s message and his stand against corruption.
Typically, on this day, people organise large marches in cities across the world to symbolise the eternal nature of Husayn’s revolution and to show they stand for freedom and human dignity..
In recent years, a tradition of walking 80km from Najaf (the resting place of Ali, the father of Husayn) to Karbala has been reignited. Every year since, the number has been rising steadily from 17 million pilgrims to at least 25 million, and People from all walks of life and all corners of the globe make the journey.
Along the all the ways to Karbala, volunteers distribute free food and drinks to those undertaking the pilgrimage, as well as offering places to relax, wash and sleep.
Today, almost 1400 years later, the Day of Arba'in is remembered by millions of people around the world. It is marked as a day to pay tribute to the sacrifice of Husayn for social justice.
Arba'in Day is now the largest annual peaceful gathering in the world, with numbers set to increase significantly every year.
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