According to this book;Dadda ‘Atta and his forty grandsons: the socio-political organisation of the Aït ‘Atta of southern Morocco, Wisbech, Cambridgeshire: MENAS Press, 1981
The Aït Atta crushed the army of Moulay Ali Cherif and defeated them at this war, as a matter of fact the complete army (of m.a.c)was wiped out.
...To the east, Moulay Ali Cherif, the founder of the present ruling dynasty of Morocco, organized the defence of the Tafilalt in 1631. A number of the most forceful Alaouite sultans (Moulay Ismael – late 17th century – Moulay Sliman, Moulay Hassan – late 19th century), tried in vain to crush the Aït Atta...
...At the same time as the Sâadians from the Dâa valley were emerging as the new rulers of Morocco (Late 15th century), an extraordinary martial society was created the Aît Atta. Dada Atta, a Berber chieftain from the bleak slopes of Jbel Saghro, was the eponymous founder of this tribe of hardened warriors. Within a few decades, the Aït Atta had overthrown the 300 year supremacy of the Maqil Arabs and imposed their own rule...
Source: http://www.itineranceplus.com/english/culturalmemo.asp?culturalID=42&ID=44&CatID=3