Complex sentence: For several centuries, Mossi peasants were both farmers and soldiers; as the Mossi Kingdoms successfully defended their territory, indigenous religious beliefs, and social structure against forcible attempts to conquer or convert them to Islam by Muslim peoples from the northwest.
Split into simpler sentences: For several centuries, Mossi peasants were both farmers and soldiers. During this time the Mossi Kingdoms successfully defended their territory, religious beliefs and social structure against forcible attempts at conquest and conversion by their Muslim neighbors to the northwest.