Ancient DNA | France | Brittany and Normandy

Are Bretons really outliers in France?

On genetic maps of France, Brittany often stands apart, closer to Wales and Ireland than to Paris. Are the Bretons a people apart? Ancient DNA and Global25 tell a different story: they are, first of all, the heirs of the Iron Age Gauls of northern France, themselves descended from the Bell Beaker people, with a British accent acquired across the Channel.

7.2Global25 distance from Upper Brittany to its nearest French neighbour, Normandy: exactly the same as between Nord and Pas-de-Calais
15 unitsseparate the Iron Age people of northern France and England: by then, the two shores of the Channel were genetically almost one population
48%steppe ancestry in Lower Brittany, the highest of the French regions we tested: the legacy of the Bell Beaker people, as in Wales

Hero image: AI generated illustration of a Gaulish trading ship with a leather sail moored at a wooden jetty in a granite harbour of southern Brittany in the first century BC. Traders in checked cloaks unload tin ingots, hides and wine amphorae while a family watches, below a Neolithic standing stone on a hill of gorse and heather. Clothing, the ship and the scene are approximations, and it is not a reconstruction of a documented event or of the individuals whose genomes are discussed here.

Every genetic study of France seems to find the same thing: Brittany stands out. In principal component plots, Breton samples drift towards Ireland and Wales; in fine-scale maps, Brittany forms its own clusters; in medical genetics, Bretons share disease variants with the Irish. It is tempting to conclude that the Bretons are a people apart, Celts at the end of the world, barely related to the rest of France.

That conclusion is wrong, or at least badly incomplete. The Bretons are not outliers in the way the Basques or the Corsicans are. Their ancestry is, overwhelmingly, the ancestry of northern Gaul, inherited from Iron Age Gauls who themselves descended from the Bell Beaker people. What makes them look different is a mix of three things: centuries of isolation at the tip of a peninsula, the highest share of Bell Beaker heritage in France, and a British layer acquired across the Channel. We read the studies and tested each point in Global25.

Brittany between Gaul and BritainKey dates, from the Bell Beakers to the genomesabout 2500 BCBell Beakers on the AtlanticSteppe-related ancestry reaches France; Brittany is a hubof the Atlantic "maritime" Beaker style.about 2000 to 1600 BCArmorican princely moundsRich Early Bronze Age graves in Brittany share gold anddaggers with Wessex, across the Channel.about 1000 to 875 BCMigrants from France into BritainPeople related to those of France contribute abouthalf the ancestry of Iron Age southern Britain.56 BCCaesar defeats the VenetiThe "Armorican" peoples include the Osismii, Veneti andRedones of Brittany, and the Unelli, Lexovii and Caletes of Normandy.4th to 7th centuryBritons settle ArmoricaMigrants from southwest Britain give Brittany itsname and the Breton language.911Normandy is foundedRollo receives the lower Seine; Norse settlers adda Scandinavian layer to northern Gaul.1532Union with FranceThe Duchy of Brittany is united with theKingdom of France.2014 to 2024The genomesFine-scale studies of Brittany and the Loire; Iron AgeGaulish genomes; the Bronze Age migration paper.Dates are approximate.
Key dates in the history of Brittany and its neighbours, from the Bell Beakers to the genomes. Dates are approximate.

Why Brittany looks different

Three large studies have mapped the genetics of western France. In 2015, Matilde Karakachoff and colleagues analysed 1,684 people from Brittany and the Pays de la Loire and found fine-scale structure, with genetic differences rising quickly with distance. They also found more linkage disequilibrium in Brittany, the signature of a smaller effective population, and a low genetic differentiation between Bretons and Irish. In 2020, Aude Saint Pierre and colleagues studied 2,184 people from all over France and found six genetic clusters matching the country's geography, history and languages, separated by barriers that follow major rivers and mountains.

The most detailed work came in 2024, when Isabel Alves, Christian Dina and colleagues analysed 3,234 people from Brittany and the lower Loire, together with six medieval genomes. They found three main groups: Western Brittany, which matches the Breton-speaking area; Eastern Brittany together with the north of the Loire; and the south of the Loire. The strongest genetic boundary was not the linguistic border inside Brittany but the Loire itself. Western Brittany differs less from Eastern Brittany than Eastern Brittany differs from the south of the Loire. The authors also found that Western Brittany had the smallest effective population of the region around the 5th century, before growing about twelvefold over the last 1,450 years. Small, isolated populations drift, and drift makes a population look distinctive on a genetic map without making it foreign.

How distinctive are the Bretons, compared with other French regions? We measured, for each French population in Global25, the distance to its nearest neighbour among the others.

Are Bretons outliers in France?Global25 distance from each French population to its nearest neighbour among the others (our analysis)0.010.020.030.040.0Corsicans41.2Marseille18.5Bearn16.7French Basques16.7Lower Brittany14.1Paris12.1Lorraine (Moselle)11.0Alsace8.0Auvergne7.4Toulouse region7.4Upper Brittany7.2Normans7.2Nord7.2Pas-de-Calais7.2Lower is more typical. Lower Brittany: Finistere, Cotes-d'Armor, Morbihan. Upper Brittany: Ille-et-Vilaine, Loire-Atlantique.
Global25 distance from each French population to its nearest neighbour among the others (our analysis). Breton subgroups are not compared with each other. Lower Brittany: Finistere, Cotes-d'Armor and Morbihan; Upper Brittany: Ille-et-Vilaine (with Rennes) and Loire-Atlantique.

Upper Brittany, the Gallo-speaking east around Rennes and Nantes, is among the most ordinary populations of France: its nearest neighbour, Normandy, sits 7.2 units away, exactly the distance between Nord and Pas-de-Calais. Lower Brittany, the Breton-speaking west, is more distinctive, at 14.1, but less so than the Basques and Bearnais of the southwest, at 16.7, and nowhere near the Corsicans, at 41. Brittany is a region with character, not a genetic island.

Gauls first

Who were the ancestors of the Bretons? Around 2500 BC, the Bell Beaker phenomenon brought steppe-related ancestry to France, and Brittany became a centre of the Atlantic "maritime" Beaker style. In 2022, Claire-Elise Fischer and colleagues published 49 genomes of Iron Age Gauls from six regions of France and found no break between the Bronze Age and the Iron Age: the Gauls descended from the Bronze Age people of France, with a strong genetic homogeneity across regions and gene flow with England and Spain. Brittany itself was Gaulish: Julius Caesar lists the Osismii, Veneti, Coriosolites and Redones among the "Armorican" peoples of the ocean coast, together with the Unelli of the Cotentin, the Lexovii of Lisieux and the Caletes of the Pays de Caux, all in today's Normandy.

We modelled Bretons and their neighbours with the three classic sources of European ancestry: western hunter-gatherers, Anatolian farmers and steppe herders.

Bretons keep the northern Gaulish balanceHunter-gatherer, early farmer and steppe ancestry (three-source model, our analysis)0%25%50%75%100%fitFrance, Bell Beaker13375031France, Early Bronze Age14444328Northern France, Iron Age13434434England, Iron Age13394838Lower Brittany today12404841Upper Brittany today11424638Normans today11434635Nord today464431Paris today484336Welsh today12404841Irish today12375246Western hunter-gathererAnatolian farmerSteppe (Yamnaya)Sources: Loschbour, Barcin, Samara Yamnaya. Fit distances x 1000 on the right.
Western hunter-gatherer, Anatolian farmer and steppe ancestry modelled with Loschbour, Barcin and Samara Yamnaya sources (our analysis). Fit distances x 1000 on the right.

The Bretons keep almost exactly the balance of the Iron Age Gauls of northern France: 43% farmer and 44% steppe ancestry in the Iron Age, 42 and 46% in Upper Brittany, 40 and 48% in Lower Brittany. The Normans sit on the same line. Paris and the Nord have moved further, with more farmer ancestry, a sign of later movements into the great cities and plains of the north. Lower Brittany has the highest steppe share of the French regions we tested, the same as Wales: Alves and colleagues found the same thing, 46% steppe ancestry in Western Brittany, comparable to Ireland, Scotland and Norway, and an excess of genetic drift shared with Bell Beaker individuals. Bretons are not less French than the rest of France: they are what northern France looked like before later mixing.

Then who are the Bretons closest to? We compared them with present-day and ancient populations.

Who are the Bretons closest to?Global25 distance from Bretons (77 people from five departments) to other populations0.05.010.015.020.025.030.0Welsh9.2Normans9.4England, Iron Age11.1English11.8Cornish11.9Normans, Manche12.6Northern France, Iron Age13.5Germanic, Migration Period14.5Dutch14.6Scots15.2Belgians16.0Irish17.1Pas-de-Calais18.2Nord21.0Paris23.8France, Bell Beaker24.0Green: populations of today. Gold: ancient groups. Lower is closer.
Global25 distance from 77 Bretons to present-day populations (green) and ancient groups (gold), our analysis. Northern France, Iron Age: 55 genomes from Picardy, the Paris basin, the Channel coast and the Manche.

The Welsh and the Normans come first, almost tied, at 9.2 and 9.4 units. Then come the Iron Age people of England, the English, the Cornish, the Normans of the Manche and the Iron Age Gauls of northern France, all between 11 and 13.5. Paris, at 23.8, is much further. The Bretons belong to a world that runs from the Cotentin to Wales.

Why Bretons look British: because the British look French

The most important result of this analysis is not about Brittany at all. In Global25, the Iron Age people of northern France and of England are only 15 units apart, closer than Paris is to Brittany today. That is the result of a long history of exchange. In the Early Bronze Age, the princely mounds of Brittany and the rich graves of Wessex shared gold work and daggers. In 2022, Nick Patterson, David Reich and colleagues showed that migrants related to the people of France reshaped southern Britain between about 1000 and 875 BC, contributing about half of the ancestry of the Iron Age population of England and Wales. Fischer and colleagues noted genetic affinities between the Iron Age groups of northwestern France and England. In 56 BC, Caesar fought the fleet of the Veneti of southern Brittany, who had received help from Britain, and in the same period the port of Hengistbury Head, in Dorset, was receiving coins from Armorica.

So when Bretons resemble the Welsh, part of the reason is that the Welsh carry an ancestry that came, three thousand years ago, from France. The Channel was a highway long before it was a border. To see where each population leans, we compared its distance to the Iron Age Gauls of northern France with its distance to the Iron Age people of England.

From Finistere to Paris: a gradient across the ChannelDistance to Iron Age northern France minus distance to Iron Age England (our analysis)-12-8-40+4+8+12Finistere+7.8Cotes-d'Armor+7.0Morbihan+4.8Rennes+0.6Ille-et-Vilaine-6.2Loire-Atlantique-4.4Normandy, Manche-7.7Normandy, Calvados-5.3Normandy, Seine-Maritime-0.4Nord-10.0Paris-8.8Irish+11.9Welsh+7.2English+7.2Cornish+5.4closer to Iron Age northern Francecloser to Iron Age EnglandThe two Iron Age poles are only 15 units apart: these are leanings, not separate origins.
For each population, distance to the Iron Age Gauls of northern France minus distance to the Iron Age people of England (our analysis). Positive values lean towards England, negative values towards northern France. The two poles are only 15 units apart.

The pattern is a clean gradient. Finistere, the Cotes-d'Armor and the Morbihan lean towards Iron Age England, as much as the Welsh and the English do. Rennes sits exactly in the middle. Ille-et-Vilaine, the Loire-Atlantique and Normandy lean towards Iron Age northern France, as do the Nord and Paris, even more. The line between the two halves follows, roughly, the old line between Breton and Gallo speech.

That western lean is most likely the mark of the Britons who crossed the sea between the 4th and the 7th century. They came from the southwest of Britain, gave the peninsula its name and its language, which is closest to Cornish, and named its western regions Domnonee and Cornouaille after Dumnonia and Cornwall. Alves and colleagues concluded that the Wales and Cornwall-related ancestry of Brittany is likely associated with these more recent migrations, and their medieval genomes from the Pays de la Loire fitted the people of northwestern France as a whole, but not those of Finistere alone. Global25 cannot separate this British layer from the older Atlantic heritage, because the two sources are so close; the size of the medieval migration remains an open question that only early medieval genomes from western Brittany could settle.

Brittany and Normandy: two halves of Armorica

For Caesar, Armorica was not only Brittany: it was the whole western seaboard of Gaul, including most of Normandy. The genomes agree. The nearest neighbour of Upper Brittany is Normandy, and the people of Rennes are closer to the Normans than to anyone else, at 8.3 units. The Normans of the Manche, in the Cotentin, are the closest of the modern populations we tested to the Iron Age Gauls of northern France, at 11.0. Normandy later received Frankish and Norse settlers, and Alves and colleagues found a German-like component in the Normans; Brittany, which remained a separate duchy until 1532, probably received less of it. But underneath, Bretons and Normans share the same Gaulish base.

So, are the Bretons outliers?

Not in the way the myth suggests. Upper Brittany is genetically as ordinary as any region of northern France. Lower Brittany stands out more, for three reasons that the data separate well: a smaller, more isolated population whose genome drifted; the highest share of Bell Beaker steppe ancestry in France, kept because the peninsula received less later mixing than the plains of the north; and a British layer, most likely from the migration that founded Brittany, on top of three thousand years of contacts across the Channel. The Bretons are, first of all, the descendants of the Iron Age Gauls of northern France, themselves the heirs of the Bell Beaker people. Their "Celtic" look is not foreign: it is the old face of northern France, with a British accent.

Some limits should be stated. Global25 is a summary of the genome and cannot measure drift directly, nor separate British and Gaulish ancestry of the Iron Age. The ancient genomes closest to Brittany are few: three Iron Age individuals from the Manche, of low coverage, and a handful of medieval genomes from the Pays de la Loire. No Iron Age or early medieval genome from western Brittany has yet been published in our dataset, and those are the samples that would date the British layer.

Key points

  • Brittany stands out on genetic maps mainly because of isolation and drift; the strongest genetic boundary in western France is the Loire, not the Breton border.
  • In Global25, Upper Brittany's nearest French neighbour, Normandy, is 7.2 units away, as close as Nord and Pas-de-Calais; Lower Brittany, at 14.1, is less distinctive than the Basques and far less than the Corsicans.
  • Bretons keep the balance of the Iron Age Gauls of northern France: about 42% farmer and 46 to 48% steppe ancestry, the highest steppe share of the French regions tested.
  • Their closest populations are the Welsh and the Normans, followed by the Iron Age people of England and of northern France.
  • The two shores of the Channel were only 15 units apart in the Iron Age, after a Bronze Age migration from France into Britain: Bretons look British partly because the British look French.
  • Western Brittany leans towards Britain, most likely because of the Britons who settled there between the 4th and 7th centuries; eastern Brittany leans towards Normandy and northern France.

Global25 coordinates used in this article

Breton departments, Normandy and other French regions, the ancient sources and a few British populations. They can be pasted directly into the Vahaduo tool.

Bretons_all_n77,0.131414,0.137756,0.058189,0.039330,0.039272,0.015219,0.002841,0.004124,0.007270,0.008965,-0.005551,0.006035,-0.014854,-0.013403,0.018400,0.004937,-0.006118,0.001282,0.000514,0.002220,0.004207,0.002375,-0.001002,0.010360,0.000481
Lower_Brittany_n32,0.131964,0.136462,0.060009,0.042949,0.038671,0.015879,0.003187,0.003844,0.006289,0.007210,-0.006161,0.005840,-0.015921,-0.013732,0.020596,0.004251,-0.007766,0.001425,0.001540,0.003709,0.003622,0.002987,-0.001213,0.010370,0.001149
Upper_Brittany_n42,0.131032,0.138596,0.056739,0.036607,0.039736,0.014648,0.002579,0.004505,0.008166,0.010227,-0.004930,0.006012,-0.014024,-0.013051,0.017136,0.005670,-0.004998,0.001143,-0.000401,0.001423,0.004807,0.001955,-0.001153,0.010185,0.000031
Breton_Finistere,0.131968,0.136499,0.061116,0.042883,0.038958,0.015995,0.005170,0.005253,0.004704,0.006571,-0.006935,0.005219,-0.015907,-0.013188,0.021268,0.004633,-0.006481,0.000782,0.000850,0.003737,0.003141,0.002888,-0.000435,0.010101,0.001134
Breton_Cotes_dArmor,0.132177,0.136715,0.060905,0.045139,0.036584,0.017535,0.001821,0.002192,0.008207,0.007950,-0.005136,0.005695,-0.014253,-0.014537,0.019612,0.001409,-0.011017,0.001045,0.000974,0.002548,0.003946,0.004359,-0.001972,0.011161,0.002275
Breton_Morbihan,0.131710,0.136081,0.056299,0.040606,0.040359,0.013705,-0.000067,0.002308,0.007947,0.007914,-0.005452,0.007515,-0.017861,-0.014136,0.020087,0.006573,-0.007171,0.003421,0.003861,0.004967,0.004421,0.001660,-0.002236,0.010122,-0.000103
Breton_Ille_et_Vilaine,0.130669,0.141362,0.053325,0.034432,0.040623,0.014112,0.002021,0.006646,0.010185,0.009586,-0.005132,0.005065,-0.013528,-0.011588,0.010260,0.007478,-0.001878,-0.000836,0.001106,-0.000375,0.005989,0.002844,-0.000986,0.009519,0.000216
Breton_Rennes,0.131252,0.138302,0.057346,0.037377,0.038815,0.014877,0.002446,0.004413,0.008258,0.009829,-0.004933,0.005821,-0.013737,-0.013500,0.018543,0.004823,-0.005863,0.001401,-0.000381,0.001821,0.004695,0.001395,-0.000705,0.011176,0.000086
Breton_Loire_Atlantique,0.129986,0.137706,0.056266,0.033850,0.044747,0.013721,0.003995,0.002954,0.005563,0.013412,-0.004709,0.008183,-0.016353,-0.011643,0.015011,0.009281,-0.002582,0.001470,-0.002037,0.000675,0.004342,0.004649,-0.004190,0.004507,-0.000503
Normans_n33,0.129138,0.138574,0.056500,0.034943,0.040558,0.013015,0.001852,0.005000,0.007871,0.008217,-0.004040,0.004991,-0.011478,-0.009217,0.015785,0.004697,-0.004488,0.001885,0.001413,0.002710,0.004976,0.003058,-0.001449,0.010257,-0.002025
Normandy_Manche,0.129872,0.140549,0.057172,0.032655,0.040900,0.013080,0.001551,0.003461,0.010819,0.008875,-0.004336,0.005410,-0.012904,-0.009771,0.016232,-0.000265,-0.007341,0.002990,0.003985,0.002164,0.004867,0.003438,-0.002650,0.007507,-0.000671
Normandy_Calvados,0.127937,0.140956,0.058378,0.032429,0.041608,0.006191,0.001269,0.007246,0.006381,0.011772,-0.002144,0.005455,-0.013885,-0.012937,0.013599,0.006974,0.000887,0.000557,-0.003595,0.005778,0.007312,0.002003,-0.004190,0.009110,-0.004622
Normandy_Seine_Maritime,0.129758,0.136398,0.055672,0.037892,0.039988,0.015705,0.002732,0.004875,0.006557,0.006265,-0.004598,0.004290,-0.009505,-0.007242,0.016320,0.006654,-0.005109,0.002011,0.001108,0.002251,0.004679,0.003300,-0.000216,0.012291,-0.002073
French_Nord,0.127686,0.140482,0.051201,0.025004,0.038382,0.009082,0.001579,0.004343,0.008270,0.012495,-0.003893,0.004377,-0.011165,-0.008879,0.012403,0.001353,-0.006021,0.002511,0.003278,0.000600,0.001606,0.001462,-0.001135,0.008135,-0.000384
French_Paris,0.127171,0.141436,0.050431,0.023990,0.040903,0.009305,0.002799,0.005454,0.011602,0.018174,-0.007706,0.006812,-0.012907,-0.010384,0.013770,0.006063,-0.001826,0.004664,0.002708,-0.000978,0.002201,0.003575,-0.001233,0.011141,-0.001905
Northern_France_IA_avg55,0.126820,0.138389,0.059887,0.038584,0.041345,0.012875,0.001231,0.005886,0.009984,0.011256,-0.004015,0.006962,-0.014669,-0.009376,0.013567,0.001904,-0.007178,0.001541,0.002603,0.001423,0.003857,0.003040,-0.002071,0.002305,-0.001615
Normandy_Manche_IA_avg3,0.139623,0.130326,0.065367,0.053403,0.033032,0.014223,0.000548,0.000154,0.014385,0.009476,-0.004276,0.007044,-0.019128,-0.009909,0.017689,0.002210,-0.010257,0.002787,0.002388,-0.001042,0.005366,0.002143,0.002301,-0.000281,-0.003034
England_MIA_LIA,0.129779,0.136413,0.061080,0.046330,0.040824,0.015618,0.002547,0.004296,0.007408,0.007442,-0.004195,0.006657,-0.014601,-0.013960,0.021424,0.006352,-0.008610,0.002043,0.001879,0.003700,0.005347,0.003303,-0.002178,0.005328,-0.001293
France_BellBeaker_avg10,0.130669,0.131003,0.059283,0.051906,0.033391,0.013833,0.001645,0.004684,0.010758,-0.001112,-0.003897,0.005980,-0.013454,-0.017051,0.017549,0.010037,0.003338,-0.000862,0.001911,0.005290,0.007587,0.000977,0.001319,0.003494,-0.000168
France_EBA_avg14,0.128864,0.135428,0.056541,0.034838,0.040777,0.013168,0.001427,0.002176,0.013265,0.015334,-0.002158,0.006359,-0.013910,-0.015296,0.014144,0.011365,0.005550,0.000452,0.002846,0.007084,0.007005,0.002985,-0.004947,-0.003916,-0.004525
Germanic_MigrationPeriod_avg104,0.130557,0.134060,0.056713,0.039710,0.038330,0.013789,0.002687,0.006712,0.003872,0.002553,-0.004032,0.004444,-0.009501,-0.005537,0.014371,0.003821,-0.005946,0.001531,0.004136,0.002814,0.003861,0.002673,0.000730,0.010658,0.000196
Welsh,0.131978,0.138163,0.060132,0.043024,0.040592,0.016622,0.003314,0.006392,0.006279,0.004337,-0.004230,0.005912,-0.012911,-0.010975,0.020596,0.005708,-0.008703,0.002356,0.003086,0.002007,0.004985,0.003852,-0.000012,0.011224,0.000808
Cornish,0.130197,0.139752,0.061355,0.043183,0.041901,0.016412,0.003435,0.006390,0.006482,0.006967,-0.004634,0.006479,-0.013745,-0.010248,0.020755,0.003172,-0.012527,0.002115,0.003761,0.003242,0.004809,0.003871,-0.000758,0.014367,0.000691
English,0.131855,0.137043,0.061788,0.044013,0.039230,0.016748,0.004985,0.005745,0.005264,0.005678,-0.004769,0.005616,-0.012589,-0.010351,0.020615,0.003552,-0.010369,0.004094,0.003685,0.002962,0.005937,0.003404,-0.003269,0.013794,0.000031
Irish,0.133361,0.134098,0.061169,0.048864,0.037788,0.019352,0.003293,0.004713,0.003568,0.002927,-0.006971,0.005840,-0.014189,-0.014076,0.025935,0.005215,-0.011145,0.001894,0.000597,0.001776,0.005114,0.001279,0.000293,0.014407,0.000661
Loschbour_WHG,0.130897,0.109677,0.203645,0.198000,0.162492,0.059125,0.015041,0.038075,0.100217,0.016219,-0.015427,-0.017235,0.019921,-0.001239,0.061346,0.070670,0.002608,0.007348,-0.008925,0.065406,0.117543,0.010387,-0.049422,-0.173639,0.019519
Barcin_Anatolian_farmer,0.112685,0.182795,0.010936,-0.100130,0.055087,-0.046854,-0.002350,-0.002769,0.046836,0.081642,0.008607,0.010191,-0.015758,0.006193,-0.040173,-0.020021,0.003520,0.000507,0.011816,-0.014132,-0.008735,0.006306,-0.010969,-0.004940,-0.004670
Yamnaya_Samara,0.125838,0.089254,0.042908,0.115456,-0.027868,0.044685,0.004491,-0.002949,-0.054858,-0.072996,0.001858,0.000350,-0.001652,-0.023610,0.037263,0.015734,0.000000,-0.001478,-0.001704,0.012506,-0.003120,0.001374,0.011229,0.018436,-0.004524

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  3. Genomics Karakachoff M, Duforet-Frebourg N, Simonet F, Le Scouarnec S, Pellen N, et al., Blum MGB, Dina C (2015). Fine-scale human genetic structure in Western France. European Journal of Human Genetics 23: 831 to 836. doi.org/10.1038/ejhg.2014.175
  4. Ancient DNA Fischer CE, Pemonge MH, Ducoussau I, Arzelier A, Rivollat M, et al., Deguilloux MF, Pruvost M (2022). Origin and mobility of Iron Age Gaulish groups in present-day France revealed through archaeogenomics. iScience 25(4): 104094. doi.org/10.1016/j.isci.2022.104094
  5. Ancient DNA Patterson N, Isakov M, Booth T, Buster L, Fischer CE, Olalde I, et al., Armit I, Reich D (2022). Large-scale migration into Britain during the Middle to Late Bronze Age. Nature 601: 588 to 594. doi.org/10.1038/s41586-021-04287-4
  6. Ancient DNA Olalde I, Brace S, Allentoft ME, Armit I, Kristiansen K, et al., Reich D (2018). The Beaker phenomenon and the genomic transformation of northwest Europe. Nature 555: 190 to 196. doi.org/10.1038/nature25738
  7. Historical source Julius Caesar, Commentaries on the Gallic War, books 3 and 7 (written in the 50s BC).
  8. Data Global25 coordinates by Davidski (Eurogenes), and the Moriopoulos Collection 2026 of averages. Admixture models and figures: ExploreYourDNA.