Migration theories

Indo-Aryan migration models[note 1] discuss scenarios around the theory of an origin from outside South Asia of Indo-Aryan peoples, an ascribed ethnolinguistic group that spoke Indo-Aryan languages, the predominant languages of North India. Proponents of Indo-Aryan origin outside of South Asia generally consider migrations into the region and Anatolia (ancient Mitanni) from Central Asia to have started around 1500 BCE, as a slow diffusion during the Late Harappan period, which led to a language shift in northern South Asia. The Iranian languages were brought into Iran by the Iranians, who were closely related to the Indo-Aryans.

The continents of North and South America were settled by Upper Paleolithic hunter-gatherers from North Asia between 20,000 and 10,000 years ago, by way of the Beringia land bridge which had formed between northeastern Siberia and western Alaska due to the lowering of sea level during the Last Glacial Maximum. The earliest populations in the Americas, between roughly 20,000 and 10,000 years ago are also known as Paleo-Indians. The settlement of the Americas from Asia is of intense interest to archaeologists and anthropologists. Advances in archaeology, Pleistocene geology, physical anthropology, and DNA analysis have shed progressively more light on the subject; however, significant questions remain unresolved.

The Migration Period was a time of widespread migrations of peoples, notably the Germanic tribes and the Huns, within or into Europe in the middle of the first millennium AD. It has also been termed in English by the German loanword Völkerwanderung and—from the Roman and Greek perspective—the Barbarian Invasions. Many of the migrations were movements of Germanic, Hunnic, Slavic, and other peoples into the territory of the then Roman Empire with or without accompanying invasions or war.