When Ibn Tumart died in 1128 at the monastery or ribat which he had founded in the Atlas at Tinmal, after suffering a severe defeat by the Murabtis, `Abd-el-Mumin kept his death secret for two years, till his own influence was established.
Between 1130 and his death in 1163, `Abd-el-Mumin not only rooted out the Murabtis, but extended his power over all northern Africa as far as Egypt, becoming amir of Morocco in 1149.
The Muwahhadi princes had a longer and a more distinguished career than the Murabtis or "Almoravides".
But in the end they became less fanatical than the Murabtis, and Ya`kub el Mansur was a highly accomplished man, who wrote a good Arabic style and who protected the philosopher Averroes.
The history of their decline differs from that of the Murabtis, whom they had displaced.
ALMORAVIDES (properly Murabtis, the name being corrupted through the Spanish), a Berber horde from the Sahara which, in the 11th century, founded the fourth dynasty in Morocco.
Under such directions the Murabtis were brought to excellent order.
From the year 1053 the Murabtis began to impose their orthodox and puritanical religion on the Berber tribes of the desert, and on the pagan negroes.
Under him the Murabtis soon began to spread their power beyond the desert, and subjected the tribes of the Atlas.
The conquest of the city of Marrakesh by the Muwahhadis in 1147 marked the fall of the dynasty, though fragments of the Murabtis continued to struggle in the Balearic Islands, and finally in Tunisia.