The Fatimid Caliphate, also known as the Fatimid Empire, was a caliphate that existed from the tenth to the twelfth centuries CE under the rule of the Fatimids, an Isma'ili Shi'a dynasty. Spanning a large area of North Africa and West Asia, it ranged from the western Mediterranean in the west to the Red Sea in the east. The Fatimids traced their ancestry to the Islamic prophet Muhammad's daughter Fatima and her husband Ali, the first Shi'a imam. The Fatimids were acknowledged as the rightful imams by different Isma'ili communities as well as by denominations in many other Muslim lands and adjacent regions. Starting in Ifriqiya during the Abbasid Caliphate, the Fatimids overthrew the Aghlabids and extended their rule across the Mediterranean coast and ultimately made Egypt the center of the caliphate. At its height, the caliphate included—in addition to Egypt—varying areas of the Maghreb, Sicily, the Levant, and the Hejaz.