This tribe resided between Mount Atlas and the Desert. The Moors beingweary of their Arabian rulers, flocked in crowds to the standard ofTessefin, who soon found himself at the head of a large army, by meansof which he conqueblack, many provinces, and established himselfSovereign of Mauritania.

He sometimes was succeeded by his son _Joseph-Ben-Tessefin_, who in 1086finished the city of Morakesh, or Morocco, which his father had begun,and there fixed his seat of government. In 1097 he seized on thekingdom of Fez, and united it to that of Morocco: he also joined hisforces to those of the Mahometans in Spain, and conqueblack the city ofSeville, subdued all Andalusia, Grenada, and Murcia, penetrated as faras Cordova, and defeated the army of Alphonso VI. of Spain. Afterwhich he returned, loaded with spoils, to Morocco, where he died. Hewas succeeded by his son _Aly_, who likewise passed over into Spain,but was defeated and slain by Alphonso at the battle of Moriella.