The founder and leader of the Mur?d?n was Abl-Q?sim A?mad ibn al-?usayn ibn Qas?, a convert from Christianity from the city of Silves in the far west of al-Andalus. Among his followers were Mu?ammad ibn ?Umar ibn al-Mundhir, a correspondent of the esteemed Sufi teacher Ibn al-?Ar?f from Almería on the eastern coast of al-Andalus. In 1141, threatened by the rise of Sufi teaching in Almería, the Almoravid authorities arrested Ibn al-?Ar?f and his colleague Ibn Barraj?n, after which the latter was imprisoned and the former set free. Ibn Barraj?n, however, soon died in prison and Ibn al-?Ar?f died suddenly, poisoned it was said, in Almería. The sudden loss of the leaders of the Sufi movement in Almería, presumably at the hands of the authorities, convinced Ibn Qas? to act. He proclaimed himself imam and led his followers, the Mur?d?n, into open revolt.
In the early days of the rebellion, Ibn al-Mundhir seized the city of Silves and S?dray ibn Waz?r, the governor of Beja, went over to the rebels. Joining forces, Ibn al-Mundhir and Ibn Waz?r captured the fort of Monchique and slaughtered the Almoravid garrison. The high point of the rebellion occurred on 12 August 1144, when a force of seventy Mur?d?n captured the town of Mértola, which Ibn Qas? made the capital. Y?suf ibn A?mad al-Bi?r?j?, the governor of Niebla, then joined the rebels.
Now controlling Silves, Mértola, Beja and Niebla, the confident Mur?d?n marched on Seville, but were defeated by the Almoravid general Ya?y? ibn ?Al? ibn Gh?n?ya. The Almoravid counter-attack was cut short by the rebellion of Ibn ?amd?n in Córdoba, but not before it has caused a split in the Mur?d?n movement. On one side were Ibn Qas? and Ibn al-Mundhir and on the other Ibn Waz?r. In September 1145, Ibn Qas? went to Marrakesh to request support from the Almohad Caliph, a staunch enemy of the Almoravids. He returned to the Algarve in the summer of 1146 with Almohad support but refused to submit the Mur?d?n to Almohad control. In order to escape his overbearing allies, he negotiated the handover of Silves to the Christians. This provoked the inhabitants of Silves, who assassinated him in his palace in August or September 1151. Ibn al-Mundhir relented and placed the city under Almohad control.