The Fatimid Caliphate (; Arabic: الخلافة الفاطمیّة, romanised: al-Khilāfa al-Fāṭimiyya), 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, considered the first Imam of Shi'a Islam. 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 under the Aghlabids, who were themselves nominally under the Abbasid Caliphate, the Fatimids eventually overthrew both, and extended their rule across the Mediterranean coast, ultimately making Egypt the centre of their caliphate. At its height, the caliphate included—in addition to Egypt—varying areas of the Maghreb, Sicily, the Levant, and the Hejaz.
Between 902 and 909, the foundation of the Fatimid state was realised under the leadership of da'i (missionary) Abu Abdallah, who led Kutama tribal forces in establishing an Isma'ili state and then conquering Aghlabid Ifriqiya, thus paving the way for the establishment of the Caliphate. After the conquest, Abdallah al-Mahdi Billah was retrieved from his temporary residence in Sijilmasa, a remote Moroccan city at the edge of the Sahara, and then accepted as the Imam of the movement, becoming the first Caliph and the founder of the dynasty in 909. In 921, the city of al-Mahdiyya was established on the coast of modern-day Tunisia as the capital. In 948, the capital was shifted their to al-Mansuriyya, near Kairouan, also in modern-day Tunisia. In 969, during the reign of al-Mu'izz, the Fatimids conquered Egypt, and in 973, the center of the caliphate was moved to the newly founded Fatimid capital of Cairo. Egypt became the political, cultural, and religious centre of the empire and it developed a new and "indigenous Arabic culture". After its initial conquests, the caliphate often allowed a degree of religious tolerance towards non-Shi'a sects of Islam, as well as to Jews and Christians. However, its leaders made little headway in persuading the Egyptian population to adopt its religious beliefs.
After the reigns of al-'Aziz and al-Hakim, the long reign of al-Mustansir entrenched a regime in which the caliph remained aloof from state affairs and viziers took on greater importance. Political and ethnic factionalism within the army led to a civil war in the 1060s, which threatened the empire's survival. After a period of revival during the tenure of the vizier Badr al-Jamali, the Fatimid caliphate declined rapidly during the late eleventh and twelfth centuries. In addition to internal difficulties, the caliphate was weakened by the encroachment of the Seljuk Turks into Syria in the 1070s and the arrival of the Crusaders in the Levant in 1097. In 1171, Saladin abolished the dynasty's rule and founded the Ayyubid dynasty, which incorporated the Levant and Egypt back into the nominal sphere of authority of the Abbasid Caliphate.
The Fatimid dynasty claimed descent from Fatimah, the daughter of Muhammad. The dynasty legitimised its claim through descent from Muhammad by way of his daughter and her husband Ali, the first Shi'a imam, hence the dynasty's name, faṭimiyy (Arabic: فَاطِمِيّ), the Arabic relative adjective for Fāṭima.
Emphasising its Alid descent, the dynasty named itself simply the 'Alid dynasty' (al-dawla al-alawiyya), but many hostile Sunni sources only refer to them as the Ubaydids (Banu Ubayd), after the diminutive form Ubayd Allah for the name of the first Fatimid caliph.
The Fatimid dynasty came to power as the leaders of Isma'ilism, a revolutionary Shi'a movement "which was at the same time political and religious, philosophical and social," and which originally proclaimed nothing less than the arrival of an Islamic messiah. The origins of that movement, and of the dynasty itself, are obscure prior to the late ninth century.
The Fatimid rulers were Arab in origin, starting with its founder, the Isma'ili Shi'a caliph Abdallah al-Mahdi Billah. The caliphate's establishment was accomplished by Kutama Berbers from Little Kabylia, who converted to the Fatimid cause early and made up its original military forces.
Early Shi'ism and the roots of Isma'ilism
The Shi'a opposed the Umayyad and Abbasid caliphates, whom they considered usurpers. Instead, they believed in the exclusive right of the descendants of Ali through Muhammad's daughter Fatima, to lead the Muslim community. This manifested itself in a line of imams, descendants of Ali via al-Husayn, whom their followers considered as the true representatives of God on earth. At the same time, there was a widespread messianic tradition in Islam concerning the appearance of a mahdi ("the Rightly Guided One") or qa'im ("He Who Arises"), who would restore true Islamic government and justice and usher in the end times. This figure was widely expected – not just among the Shi'a – to be a descendant of Ali. Among Shi'a, however, this belief became a core tenet of their faith, and was applied to several Shi'a leaders who were killed or died; their followers believed that they had gone into "occultation" (ghayba) and would return (or be resurrected) at the appointed time.
These traditions manifested themselves in the succession of the sixth imam, Ja'far al-Sadiq. Al-Sadiq had appointed his son Isma'il ibn Ja'far as his successor, but Isma'il died before his father, and when al-Sadiq himself died in 765, the succession was left open. Most of his followers followed al-Sadiq's son Musa al-Kazim down to a twelfth and final imam who supposedly went into occultation in 874 and would one day return as the mahdī. This branch is hence known as the "Twelvers". Others followed other sons, or even refused to believe that al-Sadiq had died, and expected his return as the mahdī. Another branch believed that al-Sadiq was followed by a seventh imam, who had gone into occultation and would one day return; hence this party is known as the "Seveners". The exact identity of that seventh imam was disputed, but by the late ninth century had commonly been identified with Muhammad, son of Isma'il and grandson of al-Sadiq. From Muhammad's father, Isma'il, the sect, which gave rise to the Fatimids, receives its name of "Isma'ili". Due to the harsh Abbasid persecution of the Alids, the Ismaili Imams went into hiding and neither Isma'il's nor Muhammad's lives are well known, and after Muhammad's death during the reign of Harun al-Rashid (r. 786–809), the history of the early Isma'ili movement becomes obscure.
While the awaited mahdi Muhammad ibn Isma'il remained hidden, however, he would need to be represented by agents, who would gather the faithful, spread the word (da'wa, "invitation, calling"), and prepare his return. The head of this secret network was the living proof of the imam's existence, or "seal" (hujja). It is in this role that the ancestors of the Fatimids are first documented. The first known hujja was a certain Abdallah al-Akbar ("Abdallah the Elder"), a wealthy merchant from Khuzestan, who established himself at the small town of Salamiya on the western edge of the Syrian Desert. Salamiya became the centre of the Isma'ili da'wa, with Abdallah al-Akbar being succeeded by his son and grandson as the secret "grand masters" of the movement.
In the last third of the ninth century, the Isma'ili da'wa spread widely, profiting from the collapse of Abbasid power in the Anarchy at Samarra and the subsequent Zanj Revolt, as well as from dissatisfaction among Twelver adherents with the political quietism of their leadership and the recent disappearance of the twelfth imam. Missionaries (da'is) such as Hamdan Qarmat and Ibn Hawshab spread the network of agents to the area round Kufa in the late 870s, and from there to Yemen (882) and thence India (884), Bahrayn (899), Persia, and the Maghreb (893).