The Arbaeen pilgrimage to Karbala is the largest religious gathering in the world, marking the 40th day after the martyrdom of Imam Hossein (AS) in the seventh-century. Imam Hossein (AS) is the third Shiite Imam and grandson of Prophet Mohammad (PBUH).
Last year, millions of Muslims from across the world, including Iran, attended the 100-km rally from Iraqi city of Najaf to Karbala where the holy shrine of Imam Hossein (PBUH) is located.
Observers believe the rally is unique in terms of quality and also the number of its participants. It starts from the holy shrine of Imam Ali (PBUH) - the first Shiite Imam - and ends up in the holy shrine of Imam Hossein (PBUH).
Imam Hossein (PBUH) was martyred in the 680 A.D. battle fought on the plains outside Karbala, a city in modern Iraq that's home to the Imam's holy shrine.
In the battle, Imam Hossein (PBUH) was decapitated and his body mutilated by Yazid's armies. All of Imam Hossein's male family members, relatives, friends, soldiers who all together formed a 72-member army were beheaded in an unequal war with a 30,000-strong army of the enemy in the desert of Karbala.
The occasion is the source of an enduring moral lesson for the Shiites.
Imam Hossein's martyrdom - recounted through a rich body of prose, poetry and song - remains an inspirational example of sacrifice to Shiites, who make up a majority of the Muslim population in Iran, Pakistan, Iraq and Bahrain.Message End/