What is the Hajj?

The annual pilgrimage is one of the great dramas of Muslim life.

Performing the Hajj at least once in a lifetime is one of the five "pillars", or duties, of Islam.

Hajj disasters

Every year about two million Muslims converge on Mecca and Medina - the two holiest places in Islam - to take part in an event which combines piety and passion.

Many Muslims save for years in order to perform the pilgrimage. They often have to travel thousands of miles. Then, once they arrive, they must brave the fierce heat of the desert as they perform the Hajj rituals.

Faith and politics

For the host country, Saudi Arabia, the event has a special importance. Saudi rulers are acutely conscious of their responsibility as custodians of the Muslim holy places.

The sheer number of pilgrims poses formidable problems. In recent years hundreds have died as a result of demonstrations, fires, stampedes - or just sunstroke and exhaustion.

The Saudi authorities have introduced a quota system to keep down the numbers. They have also tried, and failed, to keep politics out of the Hajj.

In 1987 hundreds of pilgrims were killed in clashes between the Saudi security forces and Iranian-led demonstrators.

Muslims are divided over whether faith and politics should mix. But many regard such a big gathering as an ideal chance to promote political causes.

So the Hajj reflects the divisions within the Muslim world, as well as the goal of Muslim solidarity.