The occasion, which falls on Thursday, marks the end of the 40-day mourning period for Imam Hossein (AS), grandson of the Prophet Muhammad (PBUH), who was martyred along with 72 of his companions in the Battle of Karbala, in southern Iraq, in 680 AD after fighting courageously for justice against the much larger army of the Umayyad caliph, Yazid I.
Each year, millions of Muslim mourners set off on a symbolic 80-kilometer walk to Karbala, where Imam Hussein's shrine is located, from the holy city of Najaf, where his father Imam Ali (AS) is buried.
Accommodating the pilgrims along the road, as well as in both Najaf and Karbala, are thousands of make-shift tents, also known as mawkibs, that provide a wide range of services from votive food to medical care.
In 2019, an estimated 14 million Shia pilgrims travelled to Iraq to attend Arba’een processions, including about two million from neighboring Iran.
Arba’een is the largest annual religious gathering in the world, with the number of pilgrims far exceeding the almost 2.5 million visitors who descend on the holy Saudi city of Mecca for the Hajj.
This year, however, only 1,500 pilgrims per country are being allowed to fly into Iraq due to the coronavirus pandemic, which has infected 391,044 Iraqis and killed 9,604 others.
All Iran-Iraq border crossings have also been closed and Iranian citizens have been barred from travelling to Iraq.
Muslims have been advised to observe the mourning in other ways such as watching online or televised commemorations from home.