Paraphrase

Agriculture and herding spread gradually throughout sub-Saharan Africa from about 2000 B.C.E. until the end of the first millennium C.E. through a process known as the Bantu migrations. After about 500 B.C.E. the knowledge of iron metallurgy was also disseminating throughout Africa. As a result of these movements, of the introduction of new nutritious foods such as bananas, and of long-distance trade, the population of Africa grew dramatically, and increasingly complex forms of government began to emerge. Most sub-Saharan African cultures were kin-based and organized into relatively small villages that were loosely allied into districts governed by a chief. Occasionally larger and more structured kingdoms and empires appeared. These larger states generally consolidated their position through controlling long-distance trade in their regions.

In the western part of the Indian Ocean, a major empire rose after Muhammad (d. 632 CE) brought Islam to the Arabian Peninsula. A century of rapid expansion brought huge territories under Muslim rule. The Umayyad and Abbasid Empires controlled territories from Spain in the west to the borders of China in the east. In the following centuries, both Islam and the Arabic language spread through much of this territory. The Arabs had already been active traders in the Indian Ocean, and Islam encouraged trade and created opportunities as it spread a universal belief system, Arabic language, and a system of law. Sufi mystical orders or brotherhoods spread and popularized Islam along the trade routes, and annual pilgrimage journeys to Makkah reflected a diverse and growing Ummah, or Muslim community carrying out this religious duty. The Muslim lands, with their growing cities, were wealthy and demand for goods of all kinds was high. Like the Chinese at the time, science, learning and the arts were prized, and production rose. Crops such as sugar, rice, hard wheat, vegetables and fruits spread from east toward the west. All sorts of imports flowed into the Arabian (Persian) Gulf and the Red Sea, and exports flowed out. Recent finds of shipwrecks from the medieval period are beginning to show the large volume of this trade, which travel accounts have described in detail.

No Muslim empire set out to control trade in the ocean, but merchant communities spread widely, and through them, Islam spread around the lands bordering the Indian Ocean. It spread along the Silk Road and into West Africa. Arab and Persian traders stopped at ports in the growing East African city-states, where a Swahili, or coastal, culture combined African, Islamic and regional influence. Trade on the Red Sea and Arabian Gulf linked to land routes and the Mediterranean trading system.