instruction: What do you know about the Fatimid Empire?
response: The Fatimid Dynasty was a Shia Ismaili Empire which existed from Tenth to the Twelfth Centuries AD (909 - 1171 CE). They were originated from the Alids & they trace their lineage to Ali-ibn-Abi-Talib, the First Shia Imam, and named after Fatima-Al-Zahra-bint-Mohammed wife of Ali-ibn-Abi-Talib & originating from the Arab. Throughout the time, their reign spanned from North Africa to the Middle East & certain parts of Europe & Asia covering present day areas of North Africa, Egypt, Sudan, Sicily, the Levant, Yemen, Multan and the Hijaz.
  
  Abdullah al-Mahdi Billah was the founder of the Fatimid Dynasty. At present certain sects of Ismaili Shia claim to be the descendants of the Fatimids including the Druze, Nizaris, Taiyabbis & the Dawoodi Bohras.