[13][14] Abd al-Mu'min was born in the village of Tagra,[15][16] near Tlemcen, in the Kingdom of the Hammadids, present-day Algeria,[2][3] into the Kumiya tribe, an Arabized section of the Berber Zenata tribal confederation.

He then was made aware of a learned and pious Faqih called Feqih Soussi (later known as Ibn Tumart) who was travelling from the east on his way to his native land in Tinmel, present-day Morocco.

[21] Traditional accounts state that after establishing his capital at Marrakesh, Abd al-Mu'min created a dilemma in that the Almohads considered it a city of heretics.

[6][29]: 202 [14]: 75  In the same year, Ibn Qasi, the ruler of Silves, was one of the first Andalusian leaders to appeal for Almohad intervention in Al-Andalus in order to stop the advance of the Christian kingdoms, whom the faltering Almoravids were unable to contain.

In 1147 Abd al-Mu'min sent a military force led by another Almoravid defector, Abu Ishaq Barraz, who captured Algeciras and Tarifa before moving west to Niebla, Badajoz, and the Algarve.

After initial Almohad setbacks, the rebellion was eventually suppressed thanks to Abd al-Mu'min's lieutenant, Umar al-Hintati, who led a force that killed al-Massi.

Abd al-Mu'min is said to have resorted to more draconian measures afterwards and initiated a purge of people he thought might be disloyal among the subject Berber tribes, allegedly resulting in around 30,000 executions.

Responding to local appeals from Muslim officials, they took control of Cordoba in 1149, saving the city from the forces of Alfonso VII.

In 1150 or 1151 Abd al-Mu'min summoned the leaders and notables of Al-Andalus under his control to Ribat al-Fath (Rabat), where he made them pledge loyalty to him, apparently as a political demonstration of his power.

Rather than destroying these tribes, he utilised them for his campaigns in al-Andalus and they also helped to quell any internal opposition from the family of Ibn Tumart.

Over the next year he stayed in Ribat al-Fath and began to gather troops within its walls with the intention of launching another expedition to Al-Andalus.

[30] He added to the traditional clan organisations of the Berbers the concept of Makhzan, a central administration staffed by Spanish Muslims.

Abd al-Mu'min also supported the arts, but in keeping with the founders' wishes, when mosques were built he kept them simple and plain compared to other structures of that time.

Naming the new fortress al-Mahdiyya or Ribat al-Fath, he intended to use it as a staging point for future campaigns on the Iberian Peninsula.