Original: In the late 7th century, North and East Africa were heavily influenced by the spread of Islam, which eventually led to the appearance of new cultures such as those of the Swahili people in East Africa, and powerful kingdoms including the Songhai Empire in the sub-saharan west.
Simplified: In the late 7th century North and East Africa were heavily influenced by the spread of Islam. That lead to the appearance of new cultures such as those of the Swahili people.