The Spanish war prompted several waves of refugees to leave for France, from 1936 until 1939, when the fall of Barcelona brought about an unprecedented exodus in the space of two weeks. Almost half a million people crossed the border through the Pyrenees in terrible conditions. This was the Retirada .
Throughout the 20 th century, hundreds of thousands of Spaniards emigrated to France looking for better living conditions. The political and economic development of the societies they left and arrived in had a huge effect on their future and their decision to settle definitively in France, or not.
The family trees of several million French people include an Italian branch, even if it isn’t always visible or clearly identified due to the gradual Gallicisation of family names which, regardless of the era, shows how they integrated to the point of blending into the rest of society. Transalpine immigration to France does in fact have a long history.
The Algerian presence in France spans over a century of unique history. Algerians fuelled an early and large migratory flow of colonials to mainland France from the second half of the 19th century. Neither French nor foreign until 1962, Algerians were in turn "indigenous", "French subjects" then "Muslim French from Algeria". This undeclared form of immigration nevertheless encountered all the difficulties of exile and, something new, drove the fight for independence from the mainland.
Europe must face up to the ageing of its population and the structural shortages of labour, which are the two main factors in pursuing immigration policies in all European countries. However, controlling migration flows and fighting illegal immigration – carried out since 2004 by the Frontex agency – continue to be the priorities, under pressure from a section of national public opinion who view immigration as a threat to their society and to what remains of the benefits of the Welfare state. Each European country has tried to process these two contradictory tensions in its own way, whereas the construction of the European Union encourages them to harmonise their migration policy.
Until the end of the Ancien Régime, the right to nationality was governed by the jus soli principle inherited from serfdom. The French Civil Code, introduced into Europe by the Napoleonic conquests, replaced jus soli with jus sanguinis. The United Kingdom and Ireland, which were not occupied by the French Empire, remained under the jus soli system, which explains the still essential distinction between the Anglo-Saxon jus soli and the jus sanguinis that prevails in most other countries.
The circulation of information and goods, the development of transport, the internationalisation of the western model of consumption, and also the search for alternatives to that model, all these effects of globalisation are helping to facilitate or generate an intensification of migration flows. And yet, the main reasons that push people to migrate remain (socio-economic situations, conflict and violence, policies), and the same applies to the reasons why immigration is needed (economic or demographic). The number of migrants has increased quickly: 77 million in 1965, 111 million in 1990, 140 million in 1997, 175 million in 2000 (2.8% of the world’s population), 281 million in 2020 ( 3.6% of the world’s population (UN), i.e., for a total population of 7.7 billion, 1 out of every 30 people.
The 1948 Universal Declaration of Human Rights states that "any person has the right to leave any country, including his own". However, mobility, as a universal right, is not guaranteed for everyone. For the inhabitants of southern-hemisphere countries, due to a lack of resources, due also to not being able to obtain the necessary visas or authorisations, the borders remain closed. For citizens of developed countries, the border represents the prospect of travel, discovery, encounters or jobs. And nowadays, retirement. It is easier for western tourists to leave for Marrakech, Ouagadougou, Shanghai or New Delhi than for Africans, Asians or Turks to visit family, go shopping or be tourists in Paris or London.