Each route is a reconstruction of a population movement that standard histories already agree on in outline: where a language or a named people is first placed, where they are next, and which later country sits on that ground. The dots move in stages. The caption names the date, who was already there, and the polity that grows out of the settlement. A line across the sea, such as the Vandal crossing to Carthage or the voyage to Madagascar, is the direction of the journey, not a road.

Homelands this old are arguments from language and archaeology. Proto-Slavic on the middle Dnieper, Austronesian on Taiwan, and Bantu on the Cameroon border are the usual readings, not excavated muster rolls. Later states — Serbia, France, Turkey, Hungary — inherit those populations. They are not founded on the day the first band arrives.

Language dots shows who speaks what now. This map is the older movement behind some of those colours.