Hajj in numbers - in 60 seconds
An estimated 2 million Muslim pilgrims have flocked to Mecca for the annual Hajj pilgrimage.
It is a ritual that is designed to promote the bonds of Islamic brotherhood and sisterhood by showing that everyone is equal in the eyes of Allah.
But this year it has been marred by the deaths on Thursday of more than 700 pilgrims in a stampede near Mecca.
The Hajj has also been overshadowed by threats from Islamic State militants and following a giant crane collapse at Mecca's Grand Mosque that killed more than 100 people.
The five-day pilgrimage occurs in the month of Dhu al-Hijja - the 12th and final month of the Islamic lunar calendar.
It is a journey that every sane adult Muslim must undertake at least once in their lives if they can afford it and are physically able.
Here are some of the numbers involved in this year's Hajj.
Video produced by Michael Hirst