Human migration denotes any movement of groups of people from one locality to another, rather than of individual wanderers. Over the course of prehistoric time and in history, humans have been known to make large migrations. This can be compared with periodic passages of groups of animals such some birds and fishes; see entry Migration.
The movement of populations in modern times has continued under the form of voluntary immigration/emigration and involuntary population exchange effected by states. There's also seasonal human migration related to agriculture. Daily human commuting can be compared to the diurnal migration of phototactic organisms in the oceans.
This article concentrates on the historical human migrations.
Overview of historical migrations
Human migration has taken place at all times and in the greatest variety of circumstances. It has been tribal, national, class and individual. Its causes have been political, economic, religious, or mere love of adventure. Its causes and results are fundamental for the study of ethnology, of political and social history, and of political economy.
In its natural origins, it includes the separate migrations first of Homo erectus then of Homo sapiens out of Africa across Eurasia, doubtless using some of the same available land routes north of the Himalayas that were later to become the Silk Road, and across the Strait of Gibraltar.
The pressures of human migrations, whether as outright conquest or byslow cultural infiltration and resettlement, have affected the grand epochs in history (e.g. the fall of the Western Roman Empire); under the form of colonization, migration has transformed the world (e.g. the prehistoric and historic settlements of Australia and the Americas). Population genetics studied in traditionally settled modern populations have opened a window into the historical patterns of migrations, a technique pioneered by Luigi Luca Cavalli-Sforza.
Forced migration (see population transfer) has been a means of social control under authoritarian regimes, yet under free initiative migration is a powerful factor in social adjustment (e.g. the growth of urban populations).
The evolution of Homo sapiens occurred in Africa, where, it seems, the first anatomically modern humans developed. It is thought that Homo sapiens then migrated into the Near East, spreading northeastwards into Europe and eastwards into Asia, from where Australasia and, later, The Americas and Oceania were populated.
Indo-European migration into Europe
In comparison to later ages, relatively little is known about the Pre-Indoeuropean inhabitants of "Old Europe". The Basque language remains from that era, as does the indigenous language in Caucasian Georgia. The speakers of Indo-European languages seem to have originated somewhere in the steppes north of the Caspian Sea and to have penetrated into Europe, into the Aegean basin and into the Iranian plateau in several separate waves. The Scythians and Sarmatians were Indo-European peoples whose homeland remained the steppes.
The Indo-European migration has variously been dated to the end of the Neolithic (Corded ware, Marija Gimbutas), the early Neolithic (Starčevo-Körös and Linearbandkeramic, Colin Renfrew) and the late Palaeolithic (Marcel Otte ).
The Great Migrations
Western historians refer to the period of migrations that separated Antiquity from the Middle Ages in Europe as the Great Migrations or as the Migrations Period. This period is further divided into two phases.
The first phase, from 300 to 500 AD, saw the movement of Germanic and other tribes and ended with the settlement of these peoples in the areas of the former Western Roman Empire, essentially causing its demise. (See also: Ostrogoths, Visigoths, Burgundians, Suebi, Alamanni Marcomanni).
The second phase, between 500 and 900 AD, saw Slavic, Turkish and other tribes on the move, re-settling in Eastern Europe and gradually making it predominantly Slavic. Moreover, more Germanic tribes migrated within Europe during this period, including the Langobards (to Italy), and the Angles, Saxons, and Jutes (to the British Isles). See also: Avars, Huns, Arabs, Vikings, Varangians. The last phase of the migrations saw the coming of the Hungarians to the Pannonian plain.
Other Old World migrations
Other migrations that happened later in the history of Europe generally did not give rise to new states, but disrupted and, to some extent, dominated policy within Europe. Examples are the invasion of the Arabic into Spain - only as late as 1492 the Spanish completed their Reconquista of the Iberian Peninsula - or the settlement of Muslims in south-eastern Europe, as a result of European armies fighting back the Turks in the Balkan, and the unsuccessful attempt to reconquer Palestine during the Crusades, despite the enormous amount of people, pilgrims and huge armies, that participated in them.
With the art of open-sea navigation involving the most confident and courageous use of the available technologies of boat-building, combined with the most sophisticated understanding of currents and prevailing winds, the Polynesians, starting with the Lapita culture, have proven to be the most successful in the art of navigation, as the Norse adventurers in the North Atlantic and the Arab traders in the Indian Ocean did not create permanent settlements. The Lapita people, which got their name from the archological site in Lapita, New Caledonia, where their characteristic pottery was first discovered, came from Austronesia, probably New Guinea. Their navigation skills took them to the Solomon Islands, around 1600 BCE, and later to Fiji and Tonga. By the beginning of the first millennium BCE, most of Polynesia was a loose web of thriving cultures who settled on the islands' coasts and lived off the sea. By 500 BCE Micronesia was completely colonized.
Polynesian migration patterns also have been studied by linguistic analysis, and recently by analyzing characteristic genetic alleles of today's inhabitants. Both methods resulted in supporting the original archaeological findings, while adding some new and surprising insights.
Migrations to the New World
Migrations and climate cycles
The modern field of climate history suggests that the successive waves of Eurasian nomadic movement throughout history have had their origins in climatic cycles, which have expanded or contracted pastureland in Central Asia, especially Mongolia and the Altai. People were displaced from their home ground by other tribes trying to find land that could be grazed by essential flocks, each group pushing the next further to the south and west, into the highlands of Anatolia, the plains of Hungary, into Mesopotamia or southwards, into the rich pastures of China.