Growing crops on mountainous terrain can make farming very difficult. This kind of problem is what started the idea of terraced gardens where parts of the mountain were flattened out kind of like steps in order to increase surface area and make it easier to farm.
The spread of Islam into the Maghreb is an example of Arab invasion of North Africa. The Arabs send Muslim army to Maghreb (modern morocco) to battle against Byzantines and allies, and finally conquer most of the North Africa were many Berbers (locals of Maghreb) join the Muslim army. After Arabs gain more power in the region, the Berbers are now ready to adopt and convert to Islam as well as the Arabic culture.
Helots this is what they were called
