"North Africa was the land of the lost causes of Islam. The land was mainly inhabited by the Berber tribe, which was practically independent of the Abbasids. The Ismaili dai Abu Abdullah arrived in the Katama land and chose Ikjan as his base, a mountain stronghold that dominated the pilgrimage route, where he began to preach the Ismaili doctrines. While he was preaching in North Africa and consolidating the secular power, Imam al-Mahdi was closely following his activities from his retreat in Salamia. The caravan of Imam al-Mahdi left Salamia and arrived in Raqada on 20th Rabi II, 297/January 6, 910, and laid the foundation of the Fatimid Caliphate. All the notables, both Arabs and non-Arabs without exception and many other people came out to receive him. He took oath of allegiance from them. He assumed power and ordered his name mentioned in the khutba and inscribed on coins. He began to develop the barren land of Maghrib. He imposed the Islamic laws, enforcing strictly in the prohibition of forbidden food and drink, and punishing severely those who tried to practice freedom in it. The following four Ismaili Imams ruled as the Fatimid Caliphs in North Africa:-

Muhammad al-Mahdi (268-322/881-934)

Al-Qaim (322-334/934-946)

Al-Mansur (334-341/946-952)

Al-Muizz (341-365/952-975)

Imam al-Muizz sent Jawhar as-Siqilli to conquer Egypt. Jawhar's march started from Kairwan with a large army on 14th Rabi I, 357/February 4, 969. He landed at the ruins of the Tulunid dynasty (254-292/868-905) on 15th Shaban, 358/July 4, 969 where he was received with honour. In short, he captured Egypt, and dispatched a messenger towards Maghrib in presence of Imam al-Muizz with the glad tidings that Egypt had fallen to the Fatimids.

Jawhar then invited Imam al-Muizz in Egypt. After making necessary appointments in Maghrib, Imam al-Muizz departed from Mansuria on 21st Shawal, 361/August 15, 972 with his family and notable persons. His caravan reached Alexandria on 23rd Shaban, 362/May 29, 973. Abu Tahir Muhammad bin Ahmad, the qadi of Egypt, accompanied by the chief men, and offered Imam al-Muizz their salutations. Towards the end of the month of Shaban, Imam al-Muizz left Alexandria and, on Saturday, the 2nd Ramzan, 363/June 6, 973, he stopped at Mina, the wharf of Egypt. Jawhar in Jazira warmly greeted him. Imam al-Muizz entered Cairo, henceforward; it became the capital of the Fatimids. Ibn Khallikan (3:380) writes that, "On arriving at Cairo, he went to the castle and entered a hall of audience where he fell prostrate in adoration of Almighty God. He then said a prayer of two rakats (i.e., the genuflections of prayer)." Henceforward, the following Nizari Ismaili Imams ruled as the Fatimid Caliphs in Egypt:-

Al-Aziz (365-386/975-996)

Al-Hakim (386-411/996-1021)

Az-Zahir (411-427/1021-1036)

Al-Mustansir (427-487/1036-1095)

Al-Nizar (487-490/1095-1097)

After the death of Imam al-Mustansir billah in 487/1097, the Fatimid Caliphate came into the hand of Musta'li, who was not designated as the successor, but ruled with the influence of vizir al-Afdal. Henceforwath, the following rulers ruled the Fatimid Caliphate:-

Musta'li (487-495/1095-1101)

Amir (495-524/1101-1130)

Hafiz (524-544/1130-1149)

Zafir (544-549/1149-1154)

Faiz (549-555/1154-1160)

Adid (555-567/1160-1171)

Finally, the Ayyubid ruler, Saladin (d. 589/1193) conquered Egypt and got an end of the Fatimid Caliphate in 567/1171 when the Nizari Ismaili Imam Ala Muhammad (561-607/1166-1210) was ruling at Alamut in Iran. 

At its apogee, the Fatimid rule extended from the shores of the Atlantic Ocean to the Red Sea encompassing Morocco, N.W. Africa, Egypt, Syria, parts of the Hijaz.