Historical origins and genetics
The Portuguese are a Southwestern European population, with origins predominantly from Southern and Western Europe. The earliest modern humans inhabiting Portugal are believed to have been Paleolithic peoples that may have arrived in the Iberian Peninsula as early as 35,000 to 40,000 years ago. Current interpretation of Y-chromosome and mtDNA data suggests that modern-day Portuguese trace a proportion of these lineages to the paleolithic peoples who began settling the European continent between the end of the last glaciation around 45,000 years ago.
Distribution of R1a
(purple) and R1b
(red). See also this map
for distribution in Europe.
Northern Iberia is believed to have been a major Ice-age refuge from which Paleolithic humans later colonized Europe. Migrations from what is now Northern Iberia during the Paleolithic and Mesolithic, links modern Iberians to the populations of much of Western Europe and particularly the British Isles and Atlantic Europe. Recent books published by geneticists Bryan Sykes, Stephen Oppenheimer and Spencer Wells have emphasized a Paleolithic and Mesolithic Iberian influence in the modern day Irish, Welsh and Scottish gene-pool as well as parts of the English. Y-chromosome haplogroup R1b is the most common haplogroup in practically all of the Iberian peninsula and western Europe.
R1b distribution in Europe
Within the R1b haplogroup there are modal haplotypes. One of the best-characterized of these haplotypes is the Atlantic Modal Haplotype (AMH). This haplotype reaches the highest frequencies in the Iberian Peninsula and in the British Isles. In Portugal it reckons generally 65% in the South summing 87% northwards, and in some regions 96%.
The Neolithic colonization of Europe from Western Asia and the Middle East beginning around 10,000 years ago reached Iberia, as most of the rest of the continent although, according to the demic diffusion model, its impact was most in the southern and eastern regions of the European continent.
A simplified map of archaeological cultures of the late Bronze Age (c. 1200 BC):
northern Urnfield culture
Starting in the 3rd millennium BC as well as in the Bronze Age, the first wave of migrations into Iberia of speakers of Indo-European languages occurred. These were later (7th and 5th centuries BC) followed by others that can be identified as Celts. 
These two processes defined Iberia's, and Portugal's, cultural landscape—Continental in the northwest and Mediterranean towards the southeast, as historian José Mattoso describes it.
The Northwest-Southeast cultural shift also shows in genetic differences:
Based on Salas et al. findings on the Haplogroup H, a cluster that is nested within haplogroup R category, is more prevalent along the Atlantic façade, including the Cantabrian coast and Portugal. It displays the highest frequency in Galicia (northwestern corner of Iberia).
The frequency of haplogroup H shows a decreasing trend from the Atlantic façade towards the Mediterranean regions.
Ethnographic and Linguistic Map of the Iberian Peninsula at about 200 BC.
This finding adds strong evidence where Galicia and Northern Portugal was found to be a cul-de-sac population, a kind of European edge for a major ancient central European migration.
Therefore, there is an interesting pattern of genetic continuity existing along the Cantabria coast and Portugal, a pattern that has been observed previously when minor sub-clades of the mtDNA phylogeny were examined.
Given the origins from Paleolithic and Neolithic settlers as well as Indo-European migrations, one can say that the Portuguese ethnic origin is mainly a mixture of pre-Celts, (Celtiberians) para-Celts such as the Lusitanians of Lusitania, and Celtic peoples such as Gallaeci of Gallaecia, the Celtici and the Cynetes of Alentejo and the Algarve.
The Romans were also an important influence on Portuguese culture; the Portuguese language derives mostly from Latin.
After the Romans, Germanic peoples namely the Suebi and Visigoths ruled for several centuries. Some of the Vandals (Silingi,Hasdingi) and Alans also remained. The highest Germanic genetic composition in the Iberian Peninsula coincides with the ancient Kingdom of the Suebi, today’s Portugal and Galicia. The Moors occupied from the 8th century until the Reconquista movement expelled them from the Algarve in 1249. Some of their population, mainly Berbers and Jews converted to Christianity and became Cristãos novos, still easily identifiable by i.e. their new Surnames. Many were subsequently forced to flee or face the Holy Inquisition and their Auto-da-fé sentencing. Other minor influences include small Viking coastal settlements between the 9th and 10th centuries in the Northern regions of Douro and Minho.
For the Y-chromosome and this one.
The Portuguese have also maintained a certain degree of ethnic and cultural specific characteristics-ratio with the Basques, since ancient times. The results of the present HLA study in Portuguese populations show that they have features in common with Basques and some Spaniards from Madrid: a high frequency of the HLA-haplotypes A29-B44-DR7 (ancient western Europeans) and A1-B8-DR3 are found as common characteristics. Many Portuguese and Basques, do not show the Mediterranean A33-B14-DR1 haplotype, confirming a lower admixture with Mediterraneans.
The Portuguese have a characteristic unique among world populations: a high frequency of HLA-A25-B18-DR15 and A26-B38-DR13, which may reflect a still detectable founder effect coming from ancient Portuguese, i.e., Oestriminis and Cynetes. According to an early genetic study, the Portuguese are a relatively distinct population according to HLA data, as they have a high frequency of the HLA-A25-B18-DR15 and A26-B38-DR13 genes. The latter is a unique Portuguese marker – the Portuguese have neither a significant contribution to their genetic pool from paleo-North Africans (A30-B18) nor Mediterraneans (A33-B14). As such, they may have remained in relative genetic isolation compared to the rest of the Iberian populations. In Europe, the A25-B18-DR15 gene is only found in Portugal, and is also observed in white North Americans and in Brazilians (very likely of Portuguese ancestry).
The pan-European (most probably Celtic) haplotype A1-B8-DR3 and the western-European haplotype A29-B44-DR7 are shared by Portuguese, Basques and Spaniards. The later is also common in Irish, southern English, and western French populations.
The A2-B7-DR15 gene is common to those, the Cornish, Austrians and Germans, showing a much more ancient link between North Africans and western and central Europeans.
R1b-5 gene cluster is a male re-expansion 15,000–13,000 years ago from Northwestern Iberia heading towards Ireland, Wales and Northern Scotland. The Rory gene cluster (R1b-14) is one of the largest re-expansions also head towards Ireland and Scotland, however featuring particularly in Irish men with Gaelic names.
The Lusitanians (or Lusitānus/Lusitani in Latin) were an Indo-European speaking people (likely Celtic) living in the Western Iberian Peninsula long before it became the Roman province of Lusitania (modern Portugal, Extremadura and a small part of Salamanca). They spoke the Lusitanian language, of which only a few short written fragments survive. Most Portuguese consider the Lusitanians as their ancestors. Although the northern regions (Minho, Douro, Trás-os-Montes) identify more with the Gallaecians.
. The speakers of Proto-Italic and Proto-Celtic later moved southwards.
It has been hypothesized that the Lusitanians may have originated in the Alps and settled in the region in the 6th century BC. Some modern scholars consider them to be indigenous and initially dominated by the Celts, before gaining full independence from them. The archaeologist Scarlat Lambrino proposed that they were originally a tribal Celtic group, related to the Lusones.
The first area settled by the Lusitanians was probably the Douro valley and the region of Beira Alta; then they moved south, and expanded on both sides of the Tagus river, before being conquered by the Romans.
The original Roman province of Lusitania was extended north of the areas occupied by the Lusitanians to include the territories of Asturias and Gallaecia but these were soon ceded to the jurisdiction of the Provincia Tarraconensis in the north, while the south remained the Provincia Lusitania et Vettones. After this, Lusitania's northern border was along the Douro river, while its eastern border passed through Salmantica and Caesarobriga to the Anas (Guadiana) river.
The Lusitanian ethnicity and particularly, their language is not totally certain. They originated from either Proto-Celtic or Proto-Italic populations who spread from Central Europe into western Europe after new Yamnaya migrations into the Danube Valley, while Proto-Germanic and Proto-Balto-Slavic may have developed east of the Carpathian mountains, in present-day Ukraine, moving north and spreading with the Corded Ware culture in Middle Europe (third millennium BCE). Alternatively, a European branch of Indo-European dialects, termed "North-west Indo-European" and associated with the Beaker culture, may have been ancestral to not only Celtic and Italic, but also to Germanic and Balto-Slavic.
Map showing the main pre-Roman tribes in Portugal and their main migrations. Turduli
movement in red, Celtici
in brown and Lusitanian in a blue colour. Most tribes neighbouring the Lusitanians were dependent on them. Names are in Latin.
The Lusitanians were a large tribe that lived between the rivers Douro and Tagus. As the Lusitanians fought fiercely against the Romans for independence, the name Lusitania was adopted by the Gallaeci, tribes living north of the Douro, and other closely surrounding tribes, eventually spreading as a label to all the nearby peoples fighting Roman rule in the west of Iberia. It was for this reason that the Romans came to name their original province in the area, that initially covered the entire western side of the Iberian peninsula, Lusitania.
Tribes, often known by their Latin names, living in the area of modern Portugal, prior to Roman rule:
- Bardili (Turduli) – living in the Setúbal peninsula;
- Bracari – living between the rivers Tâmega and Cávado, in the area of the modern city of Braga;
- Callaici – living along and north of the Douro;
- Celtici – Celts living in Alentejo;
- Coelerni – living in the mountains between the rivers Tua and Sabor;
- Cynetes or Conii – living in the Algarve and the south of Alentejo;
- Equaesi – living in the most mountainous region of modern Portugal;
- Grovii – a mysterious tribe living in the Minho valley;
- Interamici – living in Trás-os-Montes and in the border areas with Galicia and León (in modern Spain);
- Leuni – living between the rivers Lima and Minho;
- Luanqui – living between the rivers Tâmega and Tua;
- Lusitani – being the most numerous and dominant of the whole region comprising most of Portugal;
- Limici – living in the swamps of the river Lima, on the border between Portugal and Galicia);
- Narbasi – living in the north of modern Portugal (interior) and nearby area of southern Galicia;
- Nemetati – living north of the Douro Valley in the area of Mondim;
- Paesuri – a dependent tribe of the Lusitanians, living between the rivers Douro and Vouga;
- Quaquerni – living in the mountains at the mouths of rivers Cávado and Tâmega;
- Seurbi – living between the rivers Cávado and Lima (or even reaching the river Minho);
- Tamagani – from the area of Chaves, near the river Tâmega;
- Tapoli – another dependent tribe of the Lusitanians, living north of the river Tagus, on the border between modern Portugal and Spain;
- Turduli – in the east of Alentejo (Guadiana Valley);
- Turduli Veteres – the "ancient Turduli" living south of the estuary of the river Douro;
- Turdulorum Oppida – Turduli living in the Portuguese region of Estremadura and Beira Litoral;
- Turodi – living in Trás-os-Montes and bordering areas of Galicia;
- Vettones – living in the eastern border areas of Portugal, and in Spanish provinces of Ávila and Salamanca, as well as parts of Zamora, Toledo and Cáceres;
- Zoelae – living in the mountains of Serra da Nogueira, Sanabria and Culebra, up to the mountains of Mogadouro in northern Portugal and adjacent areas of Galicia.
- Oestriminis also referred to as Sefes and supposedly linked to the
Cempsi – there isn’t a consensus regarding their exact origins and location. They are believed to have been the first known humans to inhabit the whole Atlantic axe covering Portugal and Galicia, the people from ‘Finis terrae’ at the end of the Western world.