Ubayd Allah al-Mahdi Billah

Ubayd Allah al-Mahdi Billah a.k.a Said ibn Husayn (Arabic: عبيد الله بن الحسين المهدي) is considered the founder of the Fatimid dynasty, the only major Shi'ite caliphate in Islam. He established Fatimid rule throughout much of North Africa. He ruled from 909 to 934.
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. It was at this time as well that he changed his name to Ubaydallah Al-Mahdi.