Reuters pictures of Hajj ceremony

Ihram is the name given to the special spiritual state in which pilgrims wear two white sheets of seamless cloth and abstain from certain actions. The Hajj (sometimes spelt Hadj or Haj also in English) is associated with the life of Islamic prophet Muhammad from the 7th century, but the ritual of pilgrimage to Mecca is considered by Muslims to stretch back thousands of years to the time of Abraham.