Muhammad ibn Mansur al-Mahdi, was the third Abbasid Caliph. He succeeded his father, al-Mansur. Al-Mahdi, whose name means "Rightly-guided" or "Redeemer", was proclaimed caliph when his father was on his deathbed. His peaceful reign continued the policies of his predecessors. Rapprochement with the Shi'ite Muslims in the Caliphate occurred under al-Mahdi's reign. The powerful Barmakid family, which had advised the Caliphs since the days of al-'Abbas as viziers, … Wikipedia
The definitive Wikipedia entry for Al-Mahdi. Wikipedia is the biggest multilingual free-content encyclopedia on the Internet. en.wikipedia.org/wiki/Al-Mahdi
