During the Postclassical Era, Africa was both culturally and politically affected by the introduction of Islam and the Arabic empires. This was especially true in the north, the Sudan region, and the east coast. However, this conversion was not complete nor uniform among different areas, and the low-level classes hardly changed their beliefs at all. Prior to the migration and conquest of Muslims into Africa, much of the continent was dominated by diverse societies of varying sizes and complexities. These were ruled by kings or councils of elders who would control their constituents in a variety of ways. Most of these peoples practiced spiritual, animistic religions. Africa was culturally separated between Saharan Africa (which consisted of North Africa and the Sahara Desert) and Sub-Saharan Africa (everything south of the Sahara). Sub-Saharan Africa was further divided into the Sudan, which covered everything north of Central Africa, including West Africa. The area south of the Sudan was primarily occupied by the Bantu peoples who spoke the Bantu language. From 1100 onward Christian Europe and the Islamic World became dependent on Africa for gold.