The Shia Muslim ritual of Arbaeen is the world's largest religious gathering and it dwarfs every other rally on the planet, writes American news internet site, the Huffington Post.
Not only does the congregation exceeds the number of pilgrims to Mecca for annual Hajj (by a factor of five, in fact), it is more significant than Hindu Kumbh Mela, since the latter is only held every third year.
There's another peculiar feature of Arbaeen. While it is a distinctively Shia spiritual exercise, Sunnis, even Christians, Yazidis, Zoroastrians, and Sabians partake in both the pilgrimage as well as serving of devotees.
This is remarkable given the exclusive nature of religious rituals, and it could only mean one thing: people regardless of color or creed see Hussein as a universal, borderless, and meta-religious symbol of freedom and compassion.
'If you want to see a living, breathing, lively religion, come to Karbala' says a young Australian man converted to Islam several years ago.
Why you have never heard of it probably has to do with the fact that the press is concerned more with negative, gory, and sensationalized tabloids, than with positive, inspiring narratives, particularly when it comes to Islam.
If a few hundred anti-immigration protestors take to the streets in London it will make headlines. The same level of airtime is awarded to a pro-democracy march in Hong Kong or an anti-Putin rally in Russia. But a gathering of twenty million in obstreperous defiance of terror and injustice somehow fails even to make it into the TV news ticker! An unofficial media embargo is imposed on the gargantuan event despite the story having all the critical elements of an eye-catching feature; the staggering numbers, the political significance, the revolutionary message, the tense backdrop, as well as originality.
But when such a story does make it through the editorial axe of major news outlets, it creates shockwaves and touches the most random people.
In fact, Arbaeen should be listed in the Guinness Book of World Records in several categories: biggest annual gathering, longest continuous dining table, largest number of people fed for free, largest group of volunteers serving a single event, all under the imminent threat of suicide bombings.
'To know what Islam teaches,' says one Mawkeb organizer (pilgrim tour organizer), 'don't look at the actions of a few hundred barbaric terrorists, but the selfless sacrifices exhibited by millions of Arbaeen pilgrims.'