As it is now well known, I2a1 is a typical European haplogroup. It is present all over the continent with maximum frequencies recorded in Bosnia (particularly among Bosnian Croats), Sardinia, Croatia, Serbia (+30%), Montenegro, Romania, Moldova, Bulgaria, and Macedonia (20-30%). The percentages of I2a1a2b-L621 clade in Slovenia, Ukraine, and Russia available on the Internet should be taken with caution because they are definitely smaller: up to 13% in Slovenia, 16% in Ukraine, and about 7-8% in Russia. (Based on the study of Andrej Zupan /2014/, and data from Ukrainian and Russian DNA projects /2021/)
Haplogroup I2a1a2b-L621, or to be precise, its subclade Y3120, is often considered as another “Slavic” haplogroup (beside R1a-Z282), which is wrong and scientifically inadmissible. The criterion of coherence is unambiguous: “Individuals from genetically distinguishable groups should not be given the same name; individuals from genetically indistinguishable ones should.” (Eisenmann, S. et al. Reconciling material cultures in archaeology with genetic data: The nomenclature of clusters emerging from archaeogenomic analysis. Sci Rep 8, 13003, 2018)
And so is the criterion of logic: If not a single subclade before Y3120, or at the same level as Y3120 was/is Slavic, or of Slavic origin, how could anything after Y3120 be Slavic, or of Slavic origin???
Haplogroups are a genetic, and not a geographical, linguistic, national, or social category. This means that they cannot be designated in compliance with the language their carriers speak, the country they live in, or religion they practice... Each haplogroup denotes a common paternal origin of the people who share it, and they all belong to the same ethno-genetic group which has had its own evolution.
In some cases, haplogroups are easily associated with certain ethno-genetic groups.
For example, it is obvious that most of today’s European R1a people are the Slavs, the R1b people are the Celts (or, to be precise: not all R1b men are the Celts, but all Celts are R1b!!), and I1a people are the “Northmen” or Germans in general. Of course, the ancestors of these people were not known by those names 3000 years ago, but they, nevertheless, inherited the same (basal) Y-DNA lineages which “genetic” Slavs, Celts, and Northmen/Germans inherit today.
Apparently, Y-chromosome studies discovered (and proved) that Slavs and Germans are not just ethno-linguistic but also indisputable ethno-genetic categories – groups of men sharing the same paternal lineages or ancestors. And, for that reason it is necessary to distinguish “I1a Germans” and “R1a Slavs” from the national Germans/Deutsche, Danes, Russians, Poles… (carriers of other haplogroups) who are “Germans” or “Slavs” according to the language they speak (ethno-linguistic) but not according to origin.
Unfortunately, even though the haplogroup I2a is believed to have been one of the haplogroups of the first anatomically modern humans to inhabit Europe, Cro-Magnons, there is no single common name for all I2a people now. Nevertheless, “I2a1 people” still represent a separate, distinct ethno-racial group, and they have always been (and will be) I2a1 people, regardless of the subclade, or nation they belong to, time flow, migrations of their ancestors, place they live in, or the language they speak. And, the most appropriate name for the haplogroup we are talking about is Dinaric-Carpathian – without any ethnic or national connotations.
Nations are mixtures of different haplogroups, but haplogroups themselves do not mix – they are inherited linearly: from father to son. Therefore, not a single I2a1a2b man participated in the ethnogenesis of the genetic/ethno-racial Slavs, but many I2a1a2b people definitely participated in the ethnogenesis of Slavic (or Germanic, Romance…) speaking nations.
The initial lack of knowledge and information regarding haplogroup I-L621 and its sub-branches was confusing and it produced (not less than) two contradicted theories about the place of origin of I-Y3120 and, particularly, its subclades Y4460, Y18331, S17250, and Z17855 which were all formed ~2100 years ago:
The debate was mostly futile, and many arguments and premises proved to be insignificant, or simply wrong. Namely, the attention was focused on the issues such as haplogroup frequency, the number of representatives, haplotype diversity, historical presuppositions…, but it turned out that these parameters were unreliable “tools” in locating the area where I-Y3120 offsprings originated, and they were of little help in explaining their development. However, in the last few years, thanks to thousands of ancient and modern DNA test results from different European countries, the fog has lifted, and it became visible that genetics “slightly” reshaped the history.
The first thing that catches the eye of an observer is the I2a1 map provided above. It unmistakably shows that the south-eastern Europe is the “source” of expansion of haplogroup I2a-Y3120, but it is not explicit whether it is the eastern or western Balkans. Still, the overall research and some crucial recent discoveries go in favour of the eastern side of the peninsula and the Romanian section of the Carpathian Mountains.
Namely, it seems that there is a general concurrence among “interested parties” that the haplogroup I2a-L621 appeared somewhere along the Lower Danube about 12.000 YBP.
There is also archeogenetic evidence that some I2a-Y3104 people lived in today’s Romania /Urziceni, Muntenia/ ~6100 years ago (~4100 BCE). This finding is rather important because Y3104 is/was the “parent” of L621 and L161 subclades.
It is even more important that the members of both of these haplogroups were found in the Balkans: one “I-L621+ man” died in Kazanlak (Bulgaria), 2500 YBP, and several “I-L161 men” died in Mokrin (Serbia) about 500 years later.
Then, the “great, great… grandson” of that L621 “Bulgarian” ended his life in Cârlomănești (Romania) at the beginning of the second millennia BCE – he was I-CTS4002+.
And, last but not least, two “I-Y3120 men” (Y3116+) were buried in Bezdanjača cave (Croatia) in 1100-1200 BCE.
(See: The genetic history of the Southern Arc: A bridge between West Asia and Europe, I. Lazaridis et al. 2022. & Žegarac, A. et al. Ancient genomes provide insights into family structure and the heredity of social status in the early Bronze Age of southeastern Europe. 2021.)
Therefore, it can be said that I-L621 and its younger branches were, beyond a reasonable doubt, inherent in south-eastern Europe during the Copper, Bronze and Iron Ages.
Nevertheless, the current state of affairs indicates that the carriers of oldest L621 lineages have managed to survive until today in central-western Europe – particularly Germany. But, no one can tell (yet) how or when they arrived in the area. In addition, the results accessible at https://www.yfull.com/tree/I-L621/ suggest that the clade Y3120 was either not part of that migration (i.e., migration happened before its formation 3400 YBP) or it “was born” somewhere else.
The two “Croatians” from Bezdanjača cave evidently support the latter proposition (and, of course, do not invalidate the former).
However, and unfortunately, this is where the story breaks. The gap is caused by the deficiency of more recent archaeological samples (from the period 500 years BCE to 500 years CE), and it can only be filled with conjectures.
Be that as it may, a thing or two can be learned from the available data from the Early Middle Ages. The oldest analysed remains of an I2-L621… man who lived in the Common Era were those from Marmara, Bursa, Turkey – 8th century (Y-3120 /Y5596?/). Then comes the skeleton from Gomolava site, Serbia – 9th century (I2-CTS4002) /https://haplogroup.info/all-ancient-dna.pdf /.
Another two I2-Y3120 samples were reported in the study titled “Cosmopolitanism at the Roman Danubian Frontier, Slavic Migrations, and the Genomic Formation of Modern Balkan Peoples” (2021). They were taken from the archaeological site known as Timacum Minus, Kuline necropolis, /Serbia/ I-VI century CE. Even so, both individuals were “placed” to the 10th century (one was directly carbon-dated) and, as well as all others from the same site (E1b, R1b, J2a), labelled as “Serbia Slavic” (?!?). This classification becomes more perplexing when you consider the actuality that not a single R1a-Z282 man (i.e. ethno-genetic Slav) was buried in any of the seven necropolises which were the subject of the study.
Of course, these results do not prove that I2-L621…Y3120 haplogroup was present in the south-eastern Europe 1500-2000 years ago. …Or anywhere else, for that matter, because the existing archeogenetic findings from the “upper” Europe reveal that the 10th century was the timeline when the I-Y3120 people started to move towards Hungary, Czech Republic, and then Poland, Ukraine, Russia (11-14th century). It is quite interesting that the discovered subclades: I-Y4882, I-Y5596, I-Y4460 mirror the status quo.
(Hungarian findings can be seen in: Neparáczki, E. et al. Y-chromosome haplogroups from Hun, Avar and conquering Hungarian period nomadic people of the Carpathian Basin. This study is significant because it unquestionably demonstrated that R1a men and I2a1 men (Y4460 and S17250-Y4882) who lived in Panonia (modern Hungary) in the 9-10th century did not belong to the same ethnic group. Namely, apart from different autosomal and Mt-DNA results, it was discovered that 75%, or 3 out of 4 R1a (Z280-CTS1211) men were lactose tolerant, while 83%, or 5 out of 6 I2a (xS17250) men were not. /Supplementary table 2/
Now, in order to set a solid foundation for further analysis, it is necessary to point out some raw facts, and expose some false theses.
First of all, the widespread and often cited sentence: “In respect of the concentration and the highest diversity of its sub-branches, the I2a-L621…→CTS10228→Y3120 originated somewhere in the Poland-Ukraine-Belarus triangle, about 2200-2400 years ago.” - IS NOT TRUE. What concentration and which sub-branches???
I-Y3120 subclades are spread all over south-eastern and north-eastern/north-western Europe. Their current distribution indicates that they had different pasts and that their younger offsprings developed in different places. Furthermore, the number of I2a1 people is greater in the north, but the concentration levels are higher in the south. …And?
What matters here is the following: south-eastern Europe (Hungary included) is the only region where all I-Y3120 subclades are clustered together. It is even more significant that the 2100 years old lineages of all Y3120 subclades are found exclusively in the Balkans. (see https://www.yfull.com/tree/I-Y3120/, and Y4460 results at https://bosnjackidnk.com/)
It should also be noted that there are some men from Montenegro, Croatia, Bosnia & Herzegovina (a dozen different surnames) who are still I-Y3120* (negative for /known/ downstream SNP-s), which implicitly increases the number of basal I-Y3120 branches present in the Balkans. (https://dnk.poreklo.rs/DNK-projekat/ )
As for diversity, it is acknowledged that haplogroups Y18331, S17250→PH908, and Z17855 are more diverse in the south, while Y4460, S17250→Y4882 and S17250→Y5596 are more diverse in the north.
Annotation: The larger I2a1 population and the “absolute” variety of Y4460, Y4882 and Y5596 subclades in the north-eastern Europe are the consequences of a continuous migration which started more than 1500 years ago and, above all, the development of younger branches. This is particularly noticeable in Poland, where one can find great overall I-Y3120 heterogeneity, many isolated (*) results, but, actually, no continuity – the only exception is Y4882→A10230→PLE07.
In order to realise the irrelevance of “number”, and limited relevance of “variety/diversity” arguments in this discussion, one should take a look at the following: The population of Montenegro is 620.000, but it is estimated that at least 2 million people in Serbia, and 1 million more around the world, have Montenegrin forebears. Who came from where?
I-Y3120 subclades – an Outline
At this moment, there are six (defined) branches immediately below Y3120 (or YP196, or S20602):
- FT76511 (FGC12098), with “members” from Serbia, Bosnia & Herzegovina (FT256359), and Poland (*). (https://www.yfull.com/tree/I-Y3120/ )
- BY154615 (FT80992) – one sample from Germany and one from Hungary, close to the Serbian border. Judging by the surname, the latter is most probably a descendant of a man who came there in the 17th or 18th century from today’s Bosnia, Croatia, or Serbia.
- The subclade Y4460 has many representatives in northern Europe, and very few in the Balkans. Some of the Y4460 people in Ukraine, Belarus, Russia… are positive for the initial branches of this subclade, and all Y4460 people in Bulgaria, Montenegro, Turkey, and Greece (?) belong to a couple of lineages formed 2100 years ago – one is exclusively southern, while the other (Greeks) is mainly “Slavic”. (The surnames of Y4460 men from western Balkans, who are akin to Bulgarians, can be seen at https://bosnjackidnk.com/baza-bez-markera/ )
The diversity of Y4460 in Hungary and (allegedly) Romania is rather conspicuous, and when everything is considered (geographical position of the countries, historical context, ancient Y-DNA, the number of “Y4460 people” south of the Danube and Sava), it is safe to say that western Dacia was the probable place from which Y4460 spread towards the north, west, and, to a much, much lesser extent, south.
However, what is even more conspicuous is the following: the younger branches (formed less than 2000 years ago), which comprise millions of representatives in eastern and western Slavic countries, have not been found in the Balkans! This could mean that:
In either case, this is the crucial, undeniable piece of information: there was no subsequent migration of I-Y4460 people (in the 6th, 7th, or later centuries) to the Balkans which could have brought the younger branches.
- The oldest lineages of Y18331 are found in Greece, Albania, and Macedonia. One relatively large cluster is located in northern Europe – predominantly in Jewish population. (https://www.yfull.com/tree/I-Y18331/) It is obvious where this Y3120 branch originated.
- The subclade S17250 was, most probably, formed somewhere in the Romania-Serbia-Hungary border triangle, but something indeed extraordinary happened 2100-1900 years ago. As it is supposed, this is when the (main) sub-branches PH908, Y4882, and Y5596 came into existence. And, for now, it looks as though PH908 developed in the western Balkan, and Y4882, Y5596 in the area from Romania to Poland.
The following facts indicate that that Y4882 and Y5596 originated north of the Danube and Sava rivers: all major clades are there; in south-eastern Europe Y4882 is represented with only one A1328 lineage, and the percentage varies from 0 to 1.5% (of all haplogroups), while Y5596 is practically inexistent.
Incidentally, it turned out that the sample SH-251 from the study Whole genome analysis sheds light on the genetic origin of Huns, Avars and conquering Hungarians was Y4882→A1328 positive. That man was buried in the second half of the 10th century in today’s Hajdú–Bihar County bordering Romania. Thus, it is safe to assume that the ancestor of A1328→FT27092 “Balkanians” (unlike his “brother” A1328→Y15928 and all his Y4882 relatives who went up north-west) individually left Pannonia 1000-1100 years ago and settled south of the Sava and Danube rivers. /https://www.yfull.com/tree/I-A1328/ /
Historically, the north-westward movement of Y4460 and emergence of Y4882 and Y5596 can be attributed to the Roman conquest of Dacia at the beginning of the 2nd century CE. After the second Dacian war (105-106) a part of the native population (including most I-Y4460 and some I-S17250 men) retreated to the western Carpathians, out of the Roman reach, and eventually mingled with the surrounding Sarmatian (Slavic) peoples.
The narrative about PH908 is very much different – almost all basal lineages are in the Balkans (15 out of 17) (https://www. yfull.com/tree/I-PH908/ ); the continuity is apparent, the diversity is remarkable; and it represents the vast majority of I2a1a2b population in Croatia, Bosnia, Serbia, and Montenegro (~2.500.000 men). This is the only I-Y3120 subclade which should be called “Dinaric”.
There are two historical realities which support the Balkan origin hypothesis of PH908.
a) Not many people in Europe know that Montenegro (a small country in the western Balkan) is still a tribal society – people view themselves as members of different clans which, in most cases, originated from one man. In the late medieval times (13-15th century), Montenegrin tribes were designated as "Arbanases" and "Vlachs" by various notaries and (predominantly Serbian) rulers and historians. Until the arrival of Turks (the second half of 15th century), Arbanases and, more importantly, Vlachs /Vlahs/ were, without exception, differentiated from Serbs, Croats, or Slavs in general. And, it has been confirmed that the medieval Vlachs were descendants of Romanized, pre-Slavic Balkan inhabitants. Recent extensive Y-DNA testing discovered that Arbanas tribes in Montenegro belong to haplogroups E-V13, J2, and R1b, and three major Vlach tribes to I2a S17250-PH908.
b) The presence of PH908 in central and eastern European countries is mostly the consequence of several well-documented migration waves which began with the Turkish conquest of the Balkans. Namely, it has been established that more than 700.000 people left south-eastern Europe (at least 400.000 of them were from Serbia alone) and settled in Hungarian and Russian empires in the 15th, 17th, and 18th century. Approximately 30% of the men belonged to haplogroup I2a1a2b and at least 70% of them carried PH908. This relocation process continued in the 19th century as well and involved thousands of people from Montenegro, Herzegovina, Croatia, Bulgaria… It is estimated that the number of their living descendants outside the Balkan Peninsula and Romania is less than 1.300.000. (~350.000 in Ukraine, and ~700.000 in Russia – calculation performed using the information from Ukrainian and Russian DNA projects /2022/)
- All the data from YFull and national DNA projects show that Z17855 subclade was undoubtedly formed in the eastern Balkans (https://www.yfull.com/tree/I-Z17855/ ) and, what’s more, most of its representatives still live in the same region. It seems that its “mild” expansion (together with the further expansion of I-Y4460, E-V13 and R1b lineages) towards the north started in the 13th and later centuries. Some Z17855 lineages are confirmed in the western Balkans too – for instance, the members of the Vlach tribe called Mirilovići from Herzegovina.
Annotation: The division “Dinaric North” and “Dinaric South” based on the marker DYS448 values 20 and 19 is out-dated and inadequate. Two of the I-Y3120 DYS448=20 branches (Z17855 and Y18331) originated in south-eastern Europe, and one of them (Z17855) is the second major haplogroup in the region.
The facts stated above specify that a (small) number of I2a-Y3120 men could have lived in lower Danube region (Bulgaria, Serbia, Romania) about 2100-2300 years ago. Considering the aforementioned findings in Croatia, it is possible that they may have been present there even throughout the entire 1st millennia BCE. However, another theory proposes that their paternal lineage arrived from the area in which members of primary I2a-L621 clades live today (Germany, Baden-Württemberg) under the influence of Celts (a tribal confederation called Volcae) who invaded Greece in 279 BCE.
In either way, one or several of those Y3120 men had (at least) six sons who became the common ancestors of all present-day Y4460, S17250, Z18755, Y18331, FT80992, and FGC12098 people in the world. In the centuries that followed some of their descendants went to the north-west and some to the south-west. And, that is how modern “Carpathian” and “Dinaric” I2a1a2b branches came into existence.
Now, if you take a look at these two maps:
you will easily see the correspondence between the territory with the highest I-Y3120 haplogroup frequency in Romania, and the territory of the Wallachian principality from the 14th century. The common denominator is obvious, isn’t it?
When this discovery is supplemented with the already presented information about numerous members of former medieval Vlach tribes and communities from Montenegro and Herzegovina who also predominantly belong to I-Y3120 subclades, the connection becomes indubitable – the expansion of I2a1-Y3120 haplogroup was correlated to the migrations of Vlachs.
And that is not all. This argument/connection does not apply to western Balkan only. Remember the “Carpathian” I-Y3120 branch(es)? It is a well known historical actuality that Vlachs routinely migrated up along the Carpathians between the 13th and 18th centuries. Some of them settled in Moravia, some in Slovakia, and some in Beskid Mountains. Hence, today we have Laccy and Wolosi in southern Poland, Moravian Wallachia in the Czech Republic, and people named Blahnik, Blahovec who inherit I-PH908 haplogroup (Blah = Vlah)… Needless to say, those are the places where the frequency of I2a1a2b is the highest in these countries.
As for Ukraine, which is sometimes suggested as the “cradle” of I-PH908, the genetic links between the I2a1 men from the Carpathian Mountains in Ukraine and the I2a1 Romanians and Moldavians were implied in the study Populations of Transcarpathia and Bukovina on the genetic landscape of surrounding regions. Regrettably, the authors failed to back up their inkling with the fact that in 1774. Vlachs constituted 85% of the overall population in that part of today’s Ukraine.*
And finally, last but not least, it should be pointed out that the word/name Vlach/Wallach (and other variants such as Vlah, Valach, Voloh, Blach, Oláh, Vlas, Ilac, Lah…) is etymologically derived from Wolkā-/Volcae/ Οὐόλκαι – the ethnonym of already mentioned Celtic tribe. Germans adopted the word in the forms Walhaz, walhs… (stranger). Via Latin, the ethnonym took on the meaning “foreigner”, “Roman” or “Romance-speaker”, and Greeks loaned it from Slavs (Vlah → Βλάχοι).
The rest is history… and genetics.
 Edvard Ehler, Daniel Vaněk, Vlastimil Stenzl, and Václav Vančata. Y-chromosomal diversity of the Valachs from the Czech Republic: model for isolated population in Central Europe. Croat Med J. 2011 Jun; 52(3): 358–367. doi: 10.3325/cmj.2011.52.358
 Utevska, Olga & Chukhraeva, M. & Agdzhoyan, Anastasiya & Atramentova, Lubov & Balanovska, E. & Balanovsky, Oleg. (2015). Популяции Закарпатья и Буковины на генетическом фоне окружающих территорий. Вісник Дніпропетровського університету. Біологія, медицина. 6. 133. 10.15421/021524.
*Two years later, the same Olga Utevska, a geneticist from Ukraine, wrote her dissertation paper in which she arbitrarily (WITHOUT ANY CORROBORATING EVIDENCE, DATA, SOURCE...!!!) stated that the greatest diversity of I2a1a2b DYS448 = 19 (!!) haplotypes was in Ukraine and Belarus. She also implied that the carriers of I2a1a2b I-PH908 haplogroup came to the Balkans with the Slavs in the V-VI century CE from the area which is a part of today’s Ukraine. However, a simple comparative review of the presence/distribution of I-S17250-PH908 DYS448=19 SNP-s or subclades (formed 1700-1800 ybp) in the Balkan and Ukraine respectively clearly shows the magnitude of her error: https://www. yfull.com/tree/I-PH908/ & https://www.familytreedna.com/groups/ukraine/dna-results