High Quality Content by WIKIPEDIA articles! Abdul'Allah al-Mahdi Billah (r. 909-934) is the founder of the Fatimid dynasty, the only major Shi'ite caliphate in Islam, and established Fatimid rule throughout much of North Africa. After establishing himself as the first Imam of the Fatimid dynasty he made claim to genealogic origins dating as far back as Fatimah, the daughter of the Prophet of Islam, Muhammad, through Husayn, Fatimah's son, and Ismail. The above interpretation of the Fatimid history is only an interpretation of some of the writers. Other authors who have extensively written on the Fatimids such as "al-Miqrizi" and "Idris Imaduddin" have denied the above theory. Also a German scholar Heinz Halm has written a different aspect of this part of History in his book The Empire of the Mahdi: The rise of the Fatemids.