The islanders buried their treasure in the rubbish heap

Dig into an Early Ceramic Age village in the Antilles and the valuables turn up in the rubbish. Personal ornaments of carnelian, greenstone, serpentinite and amethyst, the most laborious objects these communities made, were placed in the midden, the household refuse heap at the edge of the settlement. The placement was deliberate. Putting a prized thing into the ground of your own village makes a claim that everyone present can watch being made, and it fixes that claim in a spot the community walks past daily. Behind the ornaments sits a harder fact. Particular islands controlled particular minerals, and the communities holding them were autonomous, competitive and watching each other closely. The finished goods travelled anyway. Settlements scattered across hundreds of kilometres of open water stayed in contact because objects like these kept moving between them, which is what a social network looks like when it has to be maintained by canoe.

Arab armies took Egypt in 642 and pushed south against the Christian kingdoms of the Upper Nile. Nubia fought hard and had little gold or grain worth seizing, so in 652 the two sides settled on terms. No Muslim would enter the country. In return Nubia would hand over a fixed number of enslaved people every year, receiving other goods in exchange. The agreement was called the Baqt and it appears to have held for several hundred years. Under its shelter the kingdoms of Makuria, whose capital stood at Dongola, and Alwa, centred on Soba near modern Khartoum, built cathedrals and monasteries at Faras, Qasr Ibrim, Sai and elsewhere and covered their walls with paintings. This is one of the oldest recorded arrangements in which an African state agreed to deliver human beings on a schedule as the price of being left alone, and it ran for centuries before any European ship reached the Atlantic coast.

By about 900 the Meillacoid tradition had become the dominant pottery of the northern Caribbean, spreading across communities that had previously made quite different things. The vessels themselves are plain: unpolished, decorated with narrow incisions, applied pieces and punched marks, made to be used. What travelled with the style was a way of farming. Meillacoid communities intensified swidden cultivation, clearing and burning plots and working them in rotation, probably with new crops arriving from South America. That shift moved people off the coasts and mangrove edges and up onto hilltops, because the priority had become access to workable soil rather than access to the shore. The sea did not stop mattering. Marine food stayed a large part of the diet, and the villages on the ridges kept sending people down to fish. The picture is of societies converging on a shared set of practices across island boundaries, which is what transculturation looks like in the ground.

At the Canas site in Puerto Rico the Saladoid and Ostiones layers sit one above the other with a clean line between them, and the early conclusion drawn from that line was that two separate cultures had occupied the site in turn. The difficulty with that reading is that nobody could find anywhere for the second culture to have come from. No source region, no migration route. So the material was examined again, and the current view is that Ostionoid pottery grew out of the Saladoid tradition in the islands themselves, with recent argument pointing to the eastern Dominican Republic and the exchanges taking place there. Other evidence supports continuity. Stone toolmaking runs straight through the transition with no equivalent break. What changed was the pottery, and pottery is the loudest thing in an excavation. The change marks the beginning of a period in which the Greater Antilles broke into regions, each developing a look of its own.