In order to answer the question of the origin of the Basque population, it is necessary to look at medieval, protohistoric and prehistoric tombs, necropolises and sites. In this way, and mainly through the analysis of bone material, a way is opened up to investigate the origin of the Basque population. Modern research on medieval populations in the three provinces of the Autonomous Community and Navarre -Cenarruza (Ziortza), Garai, Astigarribia, Ordoñana, Karrantza, Orreaga, Alaiza, etc.- is directed, on the one hand, at the origins of the Basque population, and, on the other hand, at the origins of the Basque population in the three provinces of the Autonomous Community and Navarre. are aimed, on the one hand, at the anthropological analysis of skulls and long bones, and on the other, at the determination of ABO blood groups, achieved by means of a modern technique that makes use of the inhibition that occurs when an antibody is incubated with a physiological serum that has a bone trituration in suspension. This science, called Paleoserology, makes it possible to know the frequencies of ABO blood groups of extinct populations, making it possible to compare them with the frequencies of their probable descendants. This would ratify, through the identity of the blood formulas, the metric and morphological concordances the Basque skulls of today and those of the Middle Ages. Similarly, research has been extended to palaeodemography and palaeopathology, reconstructing the way of life of the human groups and the diseases they suffered from. An example of this is the tomb under an apple tree of the Anda family in the 12th century wall of Vitoria, where a young girl of less than 20 years of age was buried with a coin inserted her lips to pay the funeral tribute, or the poor state of the teeth of the very young dead population, or the anomalies of a scaphocephalic (keel-shaped) skull, or the arthritic stigmata that often appear in the joints. Furthermore, the skeletal remains from the Cenarruza Collegiate Church are of great socio-demographic value if we take into account the type of people they seem to belong to. On the other hand, the parish archives of some Biscayan counties (Arratia and Encartaciones) are making it possible to clarify the biodynamics of these two human groups over four centuries in terms of the pulse of migration (gene flow) and the behaviour in the choice of spouse and are also making it possible to clarify the repercussion that both factors have had on the possible homogenisation of the population or, on the contrary, the effect they have had on the relative isolation that could lead to a certain local differentiation with respect to the surrounding populations.
The uniqueness of the Basque surnames compiled in the archives reflects a toponymic value in 70% of them, highlighting the importance of relief in the thinking or mentality of the Basque ethnic group: bridges, mountains, churches and valleys shape the identity of families or relatives. Computer statistics are used to record the formation of 10,000 Biscayan families in 300 years; we believe that it is not necessary to underline the value of such an analysis for the historical demography of the Basque Country. Without counting the important Early Middle Ages necropolis of more than 110 tombs found in the west of the Rioja Alavesa, especially those of Santa Eulalia, Labastida, etc., if we go deeper into the history of the Basque Country, we can find the necropolis of Santa Eulalia and Labastida, if we go into the Romanisation period and, especially, into the settlements of Celtiberian Spain, we find a village very rich in archaeological materials, as in La Hoya, where the scarce remains of adults a Mediterranean typology; this population was located on both banks of the river Ebro and, as n by the traumatisms of the skeletal materials, they suffered attacks from warrior peoples coming from the Meseta. The population prior to the Iron Age and the Indo-European settlements, starting in the Neolithic period, was made up of shepherds who climbed up from the Ebro valley to the mouths of the rivers Bayas, Altube, Nervión, etc. In their dolmens - for example, Peciña, la Huesera, Egilaz, etc. - they left human remains of Mediterranean type, some of them close to the so-called western Pyrenean type. The sites found in the burial caves of Alava (Gobaederra, El Lechón, etc.) are later than those in La Rioja and in them, especially in the former, the original type from Euskal Herria begins to appear more often. Aranzadi has stated that in the population of the dolmens of Aralar (Arraztaran, Pagobakoitza, Zinekogurutze), the Pyrenean-Western type can be clearly perceived in the skulls with curved temples, low palates and convex or bombiform rear norm. Something similar occurs at the Santimamiñe site and in the Atxeta cave. Eguren has stated that he has found small quantities of skulls with a clearly Basque appearance in a dolmen at Cuartango. Comparisons with Fusté's Mediterranean series have confirmed this statement.
The error of the French anthropologists Marquer and Riquet lies precisely in having brought together in the same series the skulls of the dolmens of Peciña and La Huesera, which belong to the two varieties called slender and strong of the Mediterranean type, with those of the region of Euskal Herria oriented towards the Atlantic, because, given that they belong to two different areas of pastoral transhumance, they are two different biogeographical areas. Something similar happens with the skeletons of the so-called "Cave of the Green Men" ("Gizon berden haitzuloa") of Urbiola (Lizarra, Navarre), which probably came from the Eastern Mediterranean and settled in lands close to copper mines, as they were close relatives of the so-called "metal prospectors", and the same happens in Asturias (Vidiago). As individuals of large stature, protruding noses and flat occiput have appeared among this seafaring population, some have claimed that all these biotypes have influenced the Basque population, stressing the kinship the Basque language and the language of these Armenian Dinarics. Leaving aside the Eneolithic sites and others very close to them (Los Husos, Kobeaga, Marizulo, etc.), it is worth looking at the Neolithic site (4000 BC) called Fuente Hoz, which is a hundred metres from the village of Pobes in Alava. It is the only Neolithic settlement in the Basque Country that is so far significant, and it is surrounded by burial caves that are chronologically much later. The skeletal pieces are very chopped up. There are about ten individuals 20 and 40 years of age, almost all of them male, of slender appearance and medium height, with major dental alterations. One specimen has a large trepanation of 5 x 5 cm in the right parietal. The trepanators used the abrasion technique, in which, in order not to damage the meningeal skins of the skull, the cranial wall was rubbed with a coarse-grained stone. The patient, who was about 20 years old, survived the operation for several months, as X-rays have confirmed that there was a clear growth of bone tissue in a concentric radial direction on the external table. The relationship they have with other Neolithic and Eneolithic peninsular peoples is remarkable because, although there are some archaic features in these, the slender Mediterranean element predominates. Apparently, these were people who in the fourth millennium BC came from the east of the peninsula up the Ebro valley, appeared in the caves of Alava and left in their skeletons the phenotype that corresponds to the Mediterranean slenderness we have been discussing. However, in comparison with the Portuguese skulls from Muge (Ferenbach, 1966), they a smaller auricular height, a greater oblique flattening, greater occipital tilt and an advancement of the porium. However, it is still too early to say that the above features suggest kinship with the western Pyrenean type. If we move forward in time to more recent times, we come to the Urtiaga site (Itziar, Gipuzkoa), which José Miguel de Barandiarán discovered in 1928 and investigated together with Aranzadi and Eguren. Some of the skulls are from the Azilian period and it seems that there is another, older one, perhaps from the Magdalenian period. Aranzadi thought that some characteristics could be observed that correspond to the Basque race and others that, however, did not coincide with this race, but with that of the Cro-Magnon. In Barandiarán's opinion, these coincidences and differences, rather than rare crossbreeding, lead us to think of a clear and local evolution of the Cro-Magnon type for the Basque breed. To conclude this article, we will mention the humerus and teeth found in the caves of Lezetxiki (Arrasate) and Axlor (Dima), which belong to the Mousterian. Both the humerus and the teeth, due to the typology of the level in which they were discovered, the level of fossilisation they , the metric characters and, in the case of the teeth, the taurodontism, they belong to the variability of the Neanderthal race.