The Horn of Africa is the hinge of the ancient trade web

Levantine trade crossed the Red Sea into the Horn of Africa, and during the later half of the first millennium BCE it ran around the Indian Ocean shores to India. Indian merchants carried the network further, to southeast Asia and the islands of south Asia. Late in the same millennium overland routes linked it across central Asia to east Asia. Sea trade also began reaching far down the eastern African coast, while at the far end of the system other sea links ran up the Atlantic face of Europe to Cornish tin and Baltic amber. What that describes is a web with many centres and many arteries, and Africa is inside it at several points. The Horn is the hinge between the Red Sea corridor and the Indian Ocean world. The eastern African coast supplied the system, and the goods that made it worth running, ivory, gold, tortoiseshell and frankincense, were African in origin and African in production.

By about 250 BCE, on the radiocarbon evidence Rouse reviews, the Cedrosan Saladoid migration had reached the northern West Indies. The colonists were selective about where they stopped. They favoured high, mountainous islands, which hold rain, carry rivers and support the luxuriant forest their farming needed. Flat, dry islands were passed over. That preference explains a good deal of later Caribbean settlement, including on Hispaniola, whose mountains and well watered valleys made it one of the most heavily populated islands in the region by 1492. This is farming logic applied to an archipelago by people who had crossed open water to reach it. They knew which land would grow their crops and they chose accordingly, across a chain more than a thousand kilometres long. The indigenous history of Haiti begins with decisions of this kind, taken two thousand years before the Spanish arrived and recorded now in charcoal, potsherds and dates.

Latin speakers had a single word family for substances that acted in ways nobody could watch. Uenenum covered a potent herb, a magical influence and a poison, and out of it came a verb meaning to bewitch or to infect, a noun for the act itself, and uenefucus, a word for the person who did such things, used of men and of women. In the late republic the Roman state grew worried enough about those people to pass a law in 81 BCE against causing sudden or unexpected death by concealed means, whether the means were chemical or magical. The law treated the two as one offence. Sixteen centuries later, courts in Martinique and Suriname were still hearing cases in which nobody could say whether the accused had used a plant, a powder or a spell, and the statutes they used descended from this one. The vocabulary carried the ambiguity across two thousand years.

A Greek commercial handbook of about 340 BC, later wrongly credited to Skylax, placed the island of Cerne twelve days' sail from the Straits of Gibraltar and said no ship could get past it for shallows, mud and weed. Phoenician merchants moored there, pitched tents on the island and ferried goods to the mainland in small boats. They took away hides of deer, lion, leopard and cattle, and the hides and tusks of elephants. The people they dealt with used ivory ornaments and cups, put ivory anklets on their women and ivory decoration on their horses, drove chariots, and made a great deal of wine from vines, which the merchants also carried off. In return came perfume, Egyptian stone, Attic pottery and jars. The tents suggest that the permanent colony Hanno had planted on Cerne was already abandoned. Cerne has never been located.