Mahdi

The Mahdi Army is a private militia in Iraq.

Ahmadis consider Mirza Ghulam Ahmed to be the Mahdi.

"Of course, my Lord. You asked what they were shouting, though. It was Mahdi! They directed the term at the young master. When they-" "At Paul?" "Yes, my Lord. They've a legend here, a prophecy, that a leader will come to them, a child of a Bene Gesserit, to lead them to true freedom. It follows the familiar messiah pattern."

Al-Afghani was a polyglot Persian who became an international agitator, aspiring [...] to unify the Muslim masses behind the Caliph (or even the Mahdi) and to become himself the Luther of an Islamic reformation.