The country of Spain was inhabited since the most remote times by populations who left various traces of their civilization: the Basques of the most ancient tribes of the peninsulathey seem to offer the most direct evidence, preserved in the refuge areas of the Pyrenees. Later the long dominion of Rome helped to unify the country; considerable progress was made in the economic field, which were at the basis of the huge demographic increase, thanks to which the population, already in the age of Augustus, was estimated to reach 6 million residents, mainly concentrated in the Guadalquivir valley and in the plains coastal eastern. The barbarian invasions largely removed the fabric already built and caused a significant process of ruralization, with a progressive decline of the urban, commercial and artisan nuclei, and a consequent demographic decline, especially in the regions that had been most flourishing during the Roman Empire.. However, this ruralization process continued only in the Christian nuclei of the North; Southern Spain was affected by the penetration of the Arabs, whose domination was instead characterized by a high degree of civilization, clearly evident not only in the political and religious fields, but also in demographic and economic terms, with the beginning of a second important phase urban, linked to the new developments of irrigated citrus, olive and vegetable crops.
Elements of refined Arab culture remained in the cities (just think of Cordoba and Granada) and in the countryside even after the invasion was repelled by the Christian rulers of the North. With the Reconquista, which saw the progressive expulsion of the Arabs, the vast central regions, previously sparsely inhabited, were populated, where the Catholic sovereigns – who had already contributed to the population of northeastern Spain – favored the development of new cities built in a good strategic position. (Ávila, Segovia, Cuenca etc.). As a consequence of this territorial reorganization policy (later, at the time of the great colonial expansion of the country, the coastal port centers were instead enhanced) the population reached 9 million residents, with strong densities, as well as in the traditional Andalusia, also in Castile and Extremadura. However later, mainly due to the great outflow of young energies towards the newly discovered lands of the New World, the population dropped to 8 million in the century. XVI, to decrease again in the following one. The sec. XVIII marked a significant change in the demographic trend of the country: the population grew quite rapidly, especially in favor of the peripheral area, which was opposed within, in a central position, the capital Madrid, purposely founded as an expression of the conception unitary and absolutist of power. Since then the increase has been constant and gradual and the population, which in 1833 counted approx. 12 million residents, had doubled a little more than a century later, despite the negative effects of the huge migratory currents and the civil war, reaching in 1955 the entity of 28.9 million residents.
It should be remembered that the emigration towards abroad it was in a first period (ca. 1860-1950) essentially turned towards Latin America: in Argentina alone they landed between 1857 and 1915 ca. 1.5 million Spaniards. Transoceanic emigration reached its peak in 1913, with approx. 230,000 departures; subsequently the migratory movement turned to Europe, especially after 1950, reaching almost 200,000 departures in 1964. At the beginning of the century. XXI live in America ca. 2.5 million Spaniards and in the rest of Europe (mainly in France, Germany and Switzerland) approx. 1.5 million. The country, thanks to the best economic prospects, since the eighties of the century. XX has in turn become an immigration destination, with over 440,000 entries in 2002. The natural demographic movement is slightly positive, thanks to a birth rate approximately one percentage point higher than the death rate. The ethnic composition of the country sees the Spanish as the majority group (44.4%), with an important percentage of Catalans (28%) and Galicians (8.2%) and a significant minority of Basques (5.5%) concentrated in the northern provinces. According to iamhigher, the population, which has exceeded 45 million residents and whose average density – relatively low for a European country – is 92 residents / km², it is distributed in an irregular way, rarefying in the more rugged and arid inland provinces (Cuenca, Guadalajara, Huesca, Teruel, Soria), which were sparsely inhabited even in the past, where the large estate has created an inert environment from the historical-economic point of view; the highest densities are found along the coast, in Catalonia (233 residents / km² , in the Comunidad Valenciana (214 residents km²), in the Basque Provinces (301 residents / km²) and in Asturias (101 residents / km²), which are the main centers of attraction for internal emigration and the archipelagos of the islands are densely populated Balearics (222 residents / km²) and the Canaries (283 residents / km²), expanding thanks to the development of tourism. In the past there has been an authentic flight from the countryside and in general from the poorest regions towards the coasts, first for commercial activities linked to transoceanic trafficking, then for urban and industrial ones.