Between the fifth and the fourth centuries BC, Oscan-speaking populations from the area of Samnium, in Central Italy, spread into the south of the Italian peninsula; here they came into close contact with the Greeks of Magna Graecia. The Greek language with which Oscan speakers interacted in this area was by no means homogeneous. In fact, the Greeks who had founded colonies in South Italy had come from various areas of mainland Greece and the eastern Mediterranean, and, as a result, the forms of Greek across this region differed significantly: Ionic around the bay of Naples and in Rhegion, on the strait of Messina; Laconian Doric in Taras and its sub-colony Heraclea, both on the Gulf of Taranto; Achaean Doric in a number of colonies in south Campania, Lucania and Bruttium; Northwest Greek in Locri Epizephyrii, in the toe of the Italian peninsula; and possibly Attic-Ionic in Thurii, a Panhellenic colony founded in the fifth century under the leadership of Athens. Then, towards the end of the fourth and the beginning of the third century, the local forms of Greek became increasingly exposed to the influence of the koine, the new ‘standard’ variety of Greek based on the dialect of Athens and employed by the increasingly dominant Macedonians.

The study of migration in the ancient world unexpectedly became a topic of the global news cycle in the summer of 2017. ‘The Story of Britain’, a BBC cartoon for schools that depicted a black soldier in Roman Britain generated Twitter exchanges, subsequently expanded into blogs, newspaper articles and think pieces around the world. Historians, archaeologists, geneticists, statisticians as well as others from outside academia contributed to a debate about the amount of ethnic diversity in Roman Britain and the origin and impact of ancient migrants to the British Isles. The editors of this volume do not expect that it will have an impact equivalent to the BBC cartoon, but we hope that the chapters within it can both contribute to the gradual disentanglement of scanty, sometimes contradictory, evidence and present new ways of looking at ancient migration, while also laying bare some of the tacit or unwarranted assumptions that have been made.