Divine kingship was invented by fishing communities in a green Sahara

Between 6000 and 4000 BCE, as populations grew, ritual and political offices in many parts of the world began to be inherited inside particular families. Africa has a distinctive version of this. Sacral chiefship and kingship, where one person holds political authority and religious authority together, was in place in Upper Egypt in the later fourth millennium BCE. Archaeology and comparative ethnography put its origins centuries earlier, in Nubia and the middle Nile basin, among Nilo-Saharan speakers, and it went on thriving for thousands of years afterwards in states across the Sahara and the Sudan belt. Ehret pushes the origin back further still. He argues the institution most likely emerged among the communities that lived off the aquatic resources of the green Sahara, possibly before the middle Holocene, and reached the herders and cultivators only later. That puts the ancestor of the divine right of kings among people who fished lakes and rivers in what is now desert.

Barrera-Mordan, in the Dominican Republic, is one of the sites that forced archaeologists to move the date of human arrival in the northern Caribbean. The material there is a stone-working complex built on flaked tools struck from cores, and it dates to around 4000 BCE. The people who made it belong to what is labelled the Lithic age. They had no pottery, and they should not be confused with the ceramic-producing groups who reached the islands thousands of years afterwards and are far better known. What the assemblage records is a specialised adaptation, worked out for a set of islands with particular stone, particular coastlines and particular food. Sites like this are how the initial migration routes from the surrounding mainland get mapped, because the tool types are the trail. Hispaniola, the island Haiti shares, was inhabited about six thousand years ago by people who knew exactly what they were doing with rock.

Genetic work on donkeys points to two separate domestications, one among communities in Somaliland and another farther north along the Red Sea Hills. People in both places would have been speaking early languages of the Cushitic branch of Afrasian, and within that branch linguists can follow a word distinguishing the domestic donkey from the wild one back to roughly 5000 BCE. The linguistic date agrees with the genetic date, and both agree with the archaeology, where domestic donkeys show up in Egypt after 4000 BCE. Three independent lines of evidence converging is what makes a case of this depth solid. Two African communities, neighbours in the Horn, took the same animal in hand at about the same time and set off consequences that reached transport, trade, warfare and the organisation of states across the ancient world. The road from Somaliland to Sumer is one of the least told routes in world history.

One animal went out from Africa to the rest of the world and changed how goods move. Modern contempt for the donkey obscures the scale of that. Centuries of Western usage have turned the animal's name into a term of abuse for stupidity, and the abuse has done real damage to the record. The donkey was the first multipurpose beast of burden in history. It carried loads and it carried riders. In the Middle East people harnessed it early to wheeled vehicles. Long distance trade in goods depended on owning donkeys, and so did the first wheeled transport anywhere. The uses people found for it very likely supplied the model for domesticating and working horses and camels later on. Every chariot in Egypt, every camel caravan crossing Arabia, every cavalry charge in the ancient world descends conceptually from an animal that Africans brought under care thousands of years before a horse carried anyone.