Confederation of 3 Berber tribes (Lamtuna, Gudula, Massufa) of the Sanhaja clan, that built an empire in Maghreb and Spain in the 11th and 12th centuries.
The Almoravids were a group of zealous Muslims, originating in southern Mauritania. Their Muslim orientation was one of simple and basic rules. Their theological foundation had been formed by Ahdallah Abdallah bni Yasin.
The Almoravids were a ruling class in the society, and they were easy to spot on the street, as they wore a face muffler called litham.
The Almoravids were based on military commanders who also were administrators, called themselves jurists (fuqaha). This authority was a fragile one, as their claim of being jurists would be heavily challenged by other Muslim groups. This challenge came to undermine their power, and became part of the reason for the fall of the Almoravids. The main group challenging this authority were the Almohads, who replaced the Almoravids in 1147.
Their presence as rulers had often fragile foundations, like in Spain were they had to use Christian guards to stay in power.
Their theology was based on a strict Malikite version of Sharia (Islamic law).
Architecture from the Almoravid period is characterized by simplicity, and with little decoration.

Chronlogical dates
1039: The Almoravid leader Abdallah bni Yasin declares holy war against the Sanhaja Berbers.
1054: The Almoravids start their conquest of Maghreb.
1056: They take control over Sijilmassa (near Rissani in modern Morocco).
1059: Yasin is killed, and Abu Bakr bni Umar of the Lamtuna tribe becomes leader of the Almoravids.
1060: Abu Bakr returns to Mauritania to fight rebels challenging the heart of the Almoravids.
1062: The Almoravids establish their capital in Marrakech (today's Morocco).
1082: The Almoravids take control over Algiers.
1085: The Almoravid leader Yusuf bni Tashufin sets over to Spain, and establishes himself in Cordoba.
1086: At the Battle of za-Zallaqa Yusuf lost the city of Toledo to the Christians. Yusuf returned to Maghreb, as he could not decide whether to conquer Spain or not, as the country was governed by weak Muslim rulers.
1090: Yusuf starts a policy of deposing the Muslim rulers, hence extending Almoravid control in Spain. He first has the leaders of Granada and Malaga removed from power.
1091: The leaders of Almería and Sevilla are removed from power as well.
1093: The leader of Badajoz is deposed, too. Now, only Rodrigo Díaz de Vivar, called El Cid, resisted the Almoravid take-over. He upheld a Muslim country around Valencia, even if he himself was a Christian.
1102: Valencia falls to the Almoravids.
1110: Saragossa is captured under the leadership of Ali bni Yusuf. This became the last victory on Spanish territory, and the Almoravids were in many ways weak rulers: In number they were few compared to local Arabs and Spanish Christians. But even more, they were forced to use 
1118: The beginning of the end, with the loss of Saragossa to the Christian kings of Spain.
1125: The beginning of the Almohad rebellion starts in the Atlas Mountains, in Tin Mal.
1147: Marrakech falls to the Almohads, and the Almoravid leaders move to first Spain and then the Balearic Isles.