africa's ancient historic period includes the rise of egyptian civilization. it also includes the development of other societies outside the nile river valley, and the interaction between these societies and civilizations outside of africa. in the late 7th century, north and east africa were heavily influenced by the spread of islam. that led to the appearance of new cultures, like the swahili people and the mali empire, whose king, musa keita i, became one of the richest and most influential people of the early 14th century. this also led to an increase in the slave trade, which had a very bad influence on africa’s development until the 19th century.