3000 BCE–300 CE: (The Fifth Age — The Era of Kingdoms, Empires, and Long-Distance Trade, Strikingly New Developments in Society, Culture, and Economy, the Sp…

3000 BCE–300 CE: (The Fifth Age — The Era of Kingdoms, Empires, and Long-Distance Trade, Strikingly New Developments in Society, Culture, and Economy, the Spread of Agriculture into Previously Marginal Zones Including African Rainforests and Northern European Temperate Regions, and the Rise of Regular Trade Relations Over Long Distances from the Early Second Millennium BCE Onward): The final period in Ehret’s five-age framework spans the last three millennia BCE and the first three centuries CE — an era marked by strikingly new developments in society, culture, and economy alongside the persistence of several earlier historical trends. As population numbers and density grew across multiple world regions, larger scales of political organization took shape, culminating in the emergence of kingdoms and, in time, empires. Peoples in several areas of the world gradually readapted their crops and agricultural practices to spread their economies into zones with climates previously marginal to farming — the northern temperate regions of North America and Europe, the rainforest zones of Africa and South America, and the previously uninhabited islands of Oceania. Note the parallelism that Ehret insists upon: African farmers were pushing into the equatorial rainforest during the same centuries that European farmers were pushing into the northern latitudes. From the early second millennium BCE onward, new developments in technology and a growing variety in manufactured goods stimulated the rise of regular trade relations over long distances. By the first millennium BCE, expanding networks of long-distance exchange rippled social, cultural, political, and commercial consequences ever more widely across the African-Eurasian portion of the world. Africa was not awaiting the arrival of commerce from abroad — it was generating its own commercial networks, participating in continental and intercontinental exchange as a full and active partner.