Warlords, foederati, princes or pirates: Exploring some characteristics of the men involved in the star cluster expansion downstream of I-Y4252

There would seem to be something remarkable about the man who was the founder of the I-Y4252 haplogroup.  We can see this clearly from the explosive expansion of his clade.  At present (September 2023) there are 22 named immediately downstream branches (Figure 1) plus four others that are, as yet, not named. This proliferation of branches suggests he must have sired many children and that his sons, likewise, inherited his prodigous libido.  Even so, to explain the exceptionally vigorous expansion we see among his immediate male descendants, this above-average rate of reproduction is not enough; some other qualities made these men unusually successful and powerful within their society.  In this article, I want to consider what attributes and advantages the founder, his sons and grandsons, may have possessed that enhanced their genetic success.  

Figure 1: Twenty-two named, immediately downstream clades of I-Y4252 (Source: FTDNA haplotree, September 2023).  In addition, four other immediately downstream branches have been identified, but, so far, only in one FTDNA customer test, and these are at present designated I-Y4252*.

From the results of over 200 Big Y tests, the FTDNA "Discover" algorithm calculates a mean estimate for the most recent common ancestor (MRCA) date of the I-Y4252 haplogroup as circa 50CE with a robust 95% CI 300BCE-300CE and hence we can have reasonable confidence that the founder lived during the Roman Iron Age (Figure 3).  Where he lived is more difficult to establish, but the modern distribution of descendant clades across north-western Europe, including the British Isles, makes it seem probable he lived among the barbarian tribes somewhere to the north of the Rhine and Danube and to the west of the Vistula.  In addition, it would seem probable that his homeland was no further north than southern Scandinavia, possibly in those areas now comprising Denmark and southern Sweden (Figure 2).

Figure 2: The geographic origin of I-Y4252 is likely within an area spanning Scandinavia and north-western Europe in parts of the present-day nations of Holland, Denmark, Germany, Sweden, and Poland. 

In 50CE, Tacitus called most of this region Germania, and he was able to name and describe the character and customs of many Germanic clans that inhabited this area.  One characteristic he reported was that among these Germanic peoples, monogamy was the general rule for familial relationships, but that this custom was not followed by their leaders and chiefs.  He commented that among these elite males, polygamy (Todd, 1980, p30) and concubinage (Karras, 2006, p145) were frequently encountered.  This observation may help us add a significant detail to our picture of the I-Y4252 founder and his family.  For males of most species, including humans, the primary limit on their reproductive success is their access to fertile females, so, multiple wives and concubines could certainly favour the expansion we see in the founders line. Hence, to begin our quest, I would suggest the I-Y4252 patriarch was very likely part of the Germanic elite, possibly the leader of a barbarian clan in Germania, at the time when Roman hegemony dominated the known world. 

Next, we should ask what it was that conferred success on a barbarian leader in Germania at this time.  Across Europe, the Iron Age saw this new, extremely versatile metal utilised primarily to increase militarism and warfare, which, in Germania especially, fostered a culture of the warrior.  Adding this detail to our picture of the I-Y4252 founder, we see a man who is dominant among his male affiliates, who very likely were a gang of effective violent killers with the aid of whom he could repeatedly slaughter or subjugate neighbouring competitors. To remain dominant in such a society, a warlord would need to satisfy the greed of his close subordinates and perhaps his wider clan by providing them with wealth, gained either as plunder from defeated enemies or as protection payments from vassal groups (Steuer, 2006). Here it is worth emphasising that the closest and most potent source of wealth for any barbarian tribe at this time would have been the global hegemon, Rome, and so we might expect a significantly successful Germanic warlord to have interactions, either of confrontation or more probably, allegiance, with the Roman state.  Many Germanic warrior groups worked for Rome as foederati during this period, and it seems to me that the I-Y4252 founder may well have been the leader of such a band. 

Hence, from these observations, we define our I-Y4252 founder as a man who is part of the elite within barbarian Germanic society and a leader of professional warriors who enjoy sustained and successful interactions with Imperial Rome.  These interactions allow the founder and his associates to increase their wealth and status through diplomacy or military force, using treaties, plunder, and trade. During the first and second centuries CE, the homeland of this aristocratic leader would be in north-west Europe or southern Scandinavia. By comparing this draft curriculum vitae with the archaeology of these regions during the early Roman Iron Age, it seems to me we may be able to identify a more precise locus for the founder's heimat.   

Figure 3: Chronology for the proliferation of clades downstream from I-Y4252.  These genetic branches appear to have formed in the three centuries between the Macromanic Wars (160-180CE) and the end of the western Roman Empire (476CE). This suggests that the increasing instability along the northern border of the Roman Empire at this time favoured the reproductive success of I-Y4252 (+) males. It is also noteworthy that this period overlaps with the Volkerwanderung of the Germanic people. Formation dates (CE, shown in square brackets) for the following 18 downstream clades have been used in the boxplot: FT94277 [71], ZS9184 [97], A10033 [144], FTA13235 [166], BY82831 [186], BY117344 [193], A7111 [208], A19385 [198], A19485 [237], Y32655 [263], FGC56815 [357], Y33765 [408], BY65456 [428], FT132671 [478], A417 [538], FTC68462 [672], FT303575 [696], BY50578 [1068]. (Click on the image to enlarge)

During the Iron Age, among the Germanic tribes, wealth and status were demonstrated in elaborate funeral practices, and the archaeology associated with these death rituals provides a large and informative source of evidence on the role and relationships of their ruling class. Elite cremations or burials were often memorialised using mounds containing boats, animals, war gear, and all manner of luxury items such as jewellery, glassware, ornaments, and gaming or musical parphenalia. On the largest Danish island of Sjælland (Zealand), near the town of Stevns, the site at Himlingøje (Figure 4) is significant in this respect (Grane, 2011).  It contains a large number of burials, apparently of all social classes but most notably including elite graves dating from the period 150-250CE (Storgaard, 2003). It is worth observing that this timespan correlates well with our MRCA date estimates based on modern genetic sampling for the expansion below I-Y4252 (Figure 3). 

At least thirteen of these elite graves contain luxury Roman imports and gold items that display wealth and power on a greater scale than any other site in Scandinavia at the time.  The earliest of these so-called "princely" graves are marked by mounds.  On excavation, two of the mounds contained no obvious human remains and are consequently considered cenotaphs, each memorialising an aristocrat whose body was not available for burial, perhaps because he or she died in a distant location or at sea. Possible support for this hypothesis may come from a third mound that contained a dismembered corpse of a young male.  This man almost certainly died in a place very distant from Himlingøje and is considered to have been dismembered so as to facilitate his transport for burial in that special cemetery.  These practices and similarities between object placements in these elite burials, together with the length of time over which the site was in use, have been interpreted as showing that Himlingøje is the burial place of an aristocratic ruling dynasty with truly "international" connections. 

Figure 4: Hypothetical expansion of I-Y4252 during the 1st millennium.  The present-day distribution of I-Y4252, based on the self-declared ancestry of tested men, shows the majority consider their known direct-male ancestry originates in the British Isles, but the clade is also present at lower density throughout western Europe. a) Expansion from the supposed birth location of the I-Y4252 founder, circa 50CE [dashed ouline].  Indicative routes and dates are a hypothetical model and should not be interpreted as anything more.  b) Imported Roman glass "circus" cup from an elite grave at Himlingøje, Sjælland (Zealand), Denmark, 2-3rd century [National Museum of Denmark] c) Map of western Baltic showing location of Himlingøje cemetery d) Grave mounds at Himlingøje.  (Click on the image to enlarge)

While I would not claim this site has any direct link with the I-Y4252 founder and his immediate decendants, it seems to me that the Himlingøje burials do exemplify the existence of a widely travelled and connected aristocratic class of a type that would have been both neccessary and capable of producing the proliferation of a genetically distinct male lineage in north-western Europe during the Imperial Period.  

The Himlingøje cemetery also shows that such an aristocratic dynasty had become established in the islands of the western Baltic and that its control over power was maintained for several generations.  This location implies the population very likely had a maritime tradition and was consequently capable of moving warriors, imigrants, or trade goods, including slaves, along the Baltic and North Sea coastlines.  In particular, such seamen may have ventured to and from the British Isles.  For me, this would be a very important attribute because of the association of many I-Y4252 descendant clades with modern British men. In addition, the only two ancient DNA, Y4252-derived samples, so far identified (Lakenheath 6 & Groningen 2), were excavated in eastern England and Holland.  Both of these locations are consistent with ancestral migrations from the western Baltic. Lakenheath 6 is the older of the two and is apparently a second-generation immigrant from NW Europe who was buried in a 5th century Anglo-Saxon cemetery in Suffolk.  Consequently, it seems reasonable to me that the Danish islands could well represent territories in which our I-Y4252 founder flourished.  

The rich burials at Himlingøje also coincided with significant changes in relations between Imperial Rome and Germania that began during the second century CE.  From the time of the prolonged rebellions against Rome, which occurred along the upper Danube and which are known as the Macromannic Wars (166-180CE), Germania became increasingly unstable (Todd, 2001).  Using the MRCA date estimates for the majority of branches immediately below I-Y4252, it would seem to have been during the next couple of centuries that further significant expansion of that clade occurred.  We may imagine that this would have been a conducive environment for the proliferation and dispersal of a warrior dynasty where instability and lawlessness favoured men bred to a culture of movement, opportunistic violence, and greed.

In all this speculation, I have not attempted to define the ethnicity of the I-Y4252 founder other than generalising that he was likely a Germanic barbarian.  This omission is quite intentional because the meaning of Germanic clan, tribal, and ethnic labels in the second and third centuries is difficult to verify.  These names and the affiliations or locations to which they apply seem to me to represent a dangerously "movable feast", depending on the source reference consulted, and so they have the potential to muddle and mislead. It seems to me this is because the ethnic composition of such groups was fluid and diverse, and I further suggest descendants of the I-Y4252 patriarch would have become mingled and mixed among Batavian, Alammani, Eruli, Saxon, or Danes as opportunity and necessity demanded.  My evidence for this conclusion is the extensive present-day distribution of descendant clades in western Europe, Scandinavia, and the British Isles. When taking this into account, I think it is fair to say that the supposed wanderings of no single Germanic group can have broadcast our patriarch's seed so widely (Figure 4).

In phylogenetic trees, nodes at which more than two branches occur are said to be polytomic, but the causes of polytomy in the human Y-chromosome are unclear.  In several previous articles, I have noted that Poznik et al. (2016) have shown that technological innovations can cause advantages to male groups and thus produce an explosive increase in the number of men carrying a certain Y-DNA haplogroup.  Resulting male social elites can retain such reproductive advantage for generations.   Dr Chris Tyler-Smith of the Wellcome Trust Sanger Institute, who led the 1000 Genomes Project, which supplied the data for the 2016 Poznik Nature Genetics paper, has stated that such rapid, star-like haplogroup bursts during the recent evolution of the human Y-chromosome likely "resulted from advances in technology that could be controlled by small groups of men.  Wheeled transport, metalworking and organised warfare are all candidate explanations".  

In previous articles, I have suggested that in the case of I-Y4252, mounted cavalry warfare and clinker built, iron rivet shipbuilding may be examples of such innovations during the first millennium. Is it too fanciful to imagine that, when charging into a skirmish mounted astride a warhorse equipped with saddle, stirrups, and bridle, or again, when holding the steering-board of a shallow-drafted, clinker built sailing ship covertly entering some foreign river estuary, the I-Y4252 "skill set" that I have proposed would use its opportunistic elan to gain control and establish dominance amongst unforeseen adversity?

In summary, it is my hypothesis that our I-Y4252 founder was a successful warrior and leader who lived in north-western Europe or southern Scandinavia during the Roman Iron Age.  He and his immediate descendants were part of an "international" elite class that ruled the Germanic tribes during much of this period.  The exceptional reproductive success of the founder and his male descendants, exemplified by the rapid genetic and geographic expansion of the I-Y4252 clade, was facilitated by polygamy and concubinage and also by technologies that enhanced both their movement and repeated success in warfare.  In turn, their priveledged status and wealth were increased by their ability to develop and sustain diplomatic, military, and trading interactions with Imperial Rome.

References

Grane, T. (2011),  Zealand and the Roman Empire, 101-111, In:The Iron Age on Zealand: Status and Perspectives Ed. Linda Boye, Royal Society of Northern Antiquaries pp308

Karras, R.M. (2006), The history of marriage and the myth of Friedelehe, Early Medieval Europe, 14 (2), 119-151 

Poznik, G.D. et al.  (2016) Punctuated bursts in human male demography inferred from 1244 worldwide Y-chromosome sequences. Nat. Genet. 48(6), 593-599

Steuer, H. (2006) Warrior Bands, War Lords, and the Birth of Tribes and States in the First Millennium AD in Middle Europe 227-236, In: Warfare and Society, Archaeological and Social Anthropological Perspectives Eds Otto, T., Thrane, H., Vandkilde, H.  Aarhus University Press

Storgaard, B. (2003) Cosmopolitan aristocrats. pp 106-125, In: The spoils of victory: The North in the shadow of the Roman Empire, Eds. Jørgensen,L., Storgaard,B. & Gebauer,L . The National Museum, Copenhagen.

Todd, M. (1980), The Barbarians - Goths, Franks and Vandals, 184pp, B.T. Batesford Ltd, London, UK

Todd, M. (2001), Migrants & Invaders, 160pp, Tempus Publishing Ltd, Stroud, UK

 

A new, clade-specific, mutation rate for I-Y33765 based on a ten generation English pedigree

Two English men in the I-Y33765 clade whose Y-chromosomes are separated by ten generations have FTDNA Big Y-700 results.  They are 4^th cousins and their direct-line male patriarch, William Clement, was born in 1801 and baptised 12^th January 1802 at St Andrew, Chew Magna, Somerset, England.  These men have identical results when tested for 111 Short Tandem Repeat (STR) markers.  By comparing their Big Y-700 analyses, their most recent shared mutation downstream of I-Y33765 is I-FT314945 (equivalent level to I-BZ4354) for which the FTDNA Discover algorithm gives a mean formation date of 1700CE. 

According to their documented pedigree the ten generations that separate the two men represent a period of 328y which indicates an average generation time of 32.8y.  Interpretation of their vcf file, Y-chromosome sequence information, has identified five SNPs that form during the pedigree.  Of these mutations three are located within CombBED regions of the Y-chromosome and each of these are recorded with >2 reads and a read quality >90% (see Table1).  None of the SNPs are associated with nucleotide insertions or deletions (INDELS).  As a consequence of meeting these several criteria it is reasonable to use these three high-confidence SNPs to obtain an observed mutation rate.  In this way, during the period recorded in the pedigree we can predict one mutation every 109.3y (328y/3SNPs).   This directly observed mutation rate k can be used to calculate the base substitution rate constant µ as follows:                                          

In 2009 next generation sequencing (NGS) was used by Xue et al. to estimate the Y-chromosome mutation rate in a 13 generation Chinese pedigree belonging to Haplogroup O3a.  Their pedigree contained four SNP mutations and using these they calculated a mutation rate of 1.0*10^-9mutations per nucleotide per year.  The scale and character of our English pedigree, and of our estimated base substitution rate, appear to be similar totheir findings.  Mutation rates that have been published based on pedigrees tend to be slightly faster than evolutionary rates based on ancient DNA or other prehistoric samples (Balanovsky, 2017).  This seems to be the case with the estimated mutation rate for our English pedigree of Y33765.

There is very close agreement between the 109.3y rate obtained using this pedigree of two English men and that of 109.5y that I reported in 2021, which was obtained using a 19 generation pedigree of two Swedish men who were also derived (+) for I-Y33765.  Assuming that the MRCA of these two descendant genealogies lived circa 400CE then some 2600y separate the documented births of the named founders in England and Sweden.  The Swedish pedigree had a slightly longer average generation time of 34.6y.     

Table 1: Single Nucleotide Polymorphisms (SNPs) within the pedigree of two male descendants of William Clement (1801-1882). Based on the documented pedigree of these men their Y-chromosomes are separated by ten generations equivalent to 328y.  The position (within combBED region), reads (greater than 2), quality and absence of INDELS, of the three SNPs shown in red are criteria that together ensure these are suitable for use in the estimation of the pedigree specific SNP mutation rate.
 

References

Balanovsky, O (2017) Toward a consensus on SNP and STR mutation rates on the human Y-chromosome, Human Genetics, 136, 575-590

Xue, Y., Wang, Q., Long, Q., Ng, BL., Swerdlow, H., Burton, J., Skuce, C., Taylor, R., Abdellah, Z., Zhao, Y., Macarthur, DG., Quail, MA., Carter, NP., Yang, H. (2009) Human Y chromosome base-substitution mutation rate measured by direct sequencing in a Deep-rooting pedigree. Current Biology 19, 1453–1457

Latest draft chart for the I-Y33765 clade of I-Y4252. This incorporates the results of a FTDNA BigY700 test, completed 16 August 2023, for Clement IN128261.

Click on image to enlarge

I-Y33765 and ancient DNA - Lakenheath 6 (ERL104 G294, LAK006)

The first two published, ancient DNA, I-L233 specimens were each excavated from archaeological sites bordering the Baltic region in north eastern Europe, one in Lithuania (Spiginas 1) and the other in the north-west of the Russian Federation (5680-13 aka VK22).  Recently, Gretzinger et al., (2022) published the genetics for two additional ancient I-L233+ males whose remains have been recovered from burials in Holland and England (Figures 1 and 2).  In their Supplementary Information the authors identify these specimens as GRO002, from Groningen, Netherlands and LAK006 from, Lakenheath, England, and they report both men are derived for the I-Y4231 mutation which is downstream from I-L233. They further refined their result for the LAK006 Y-haplogroup to I-Y4252 and theirs is the first report of this clade in an ancient DNA sample.  This clade is particularly noteworthy because its formation precedes a period of extremely rapid genetic expansion with nineteen branches forming immediately downstream (FTDNA, 2023a).  Subsequent to the publication of the Nature article (Gretzinger et al., 2022) the Y-haplogroup of LAK006 was again refined and has now been assigned to one of these downstream clades, I-A19485 (FTDNA, 2023b).  At the present time, this I-A19485 haplogroup has been reported in FTDNA customer samples from men with paternal ancestry in England, the Netherlands and Poland (FTDNA 2023c). 

Depending on the source reference consulted, the LAK006 specimen is referred to by several designations.  Its original excavation number is G294, but, as already stated, in the recent genetic study it is called LAK006, and in online sources, notably FamilyTreeDNA, this has been expanded to "Lakenheath 6". In what follows I will to use this latter form because it seems to me it has a descriptive clarity that is helpful.

So, to be clear, this article will review the published reports that relate to the Lakenheath 6 skeleton and to the context in which it was found. I will also briefly consider how the identification of this individuals Y-DNA haplogroup may help our understanding of the rapid genetic and geographic expansion which seems to have occurred soon after the I-Y4252 mutation was formed.   

Figure 1 : The phylogenetic relationship between Lakenheath 6 (aka ERL104 G294 or LAK006) and other ancient DNA samples close to the I-Y33765 clade. In April 2023 the FTDNA phylogenetic Y-tree shows nineteen clades, including I-Y33765 and I-A19485, immediately downstream of I-Y4252.

To begin, let's consider what is known about the archaeological context of the Lakenheath 6 skeleton.  The bones are those of a young adult male and they were recovered from one of several early Anglo-Saxon cemeteries excavated in the parish of Eriswell, Suffolk. This part of Suffolk borders the Fens and, like much of East Anglia, is rich in early Anglo-Saxon archaeology since it was in this part of England that Germanic migrant communities from north-western Europe established themselves during the early 5th century. A characteristic of these first "English Settlements" are cemeteries that demonstrate a variety of mortuary practices associated with cremation and inhumation burials. Between 1997 and 2008, a group of three such cemeteries, containing in total 427 inhumation graves and at least 8 cremation burials, were excavated by Suffolk Archaeology on ground owned by the UK Ministry of Defence at RAF Lakenheath (Caruth & Hines, 2018). The excavation team particularly noted that the small number of cremations were only a fraction of those that may have originally occurred judging by the significant amounts of dispersed cremated human bone in the vicinity.  

Figure 2: Lakenheath 6 and other ancient DNA samples in relation to the putative origin of I-Y33765 in Tjust, Sweden.

These Anglo-Saxon burials have been dated to between the latter half of the 5th and the late 7th century and are distributed between the three, very closely separated, cemeteries which have been designated ERL104 (West), ERL046 (Central) and ERL114 (East).  The earliest burials are in ERL104, starting with the cremations after which inhumations begin at that site and at ERL046 and ERL114 and continue until about the third quarter of the 6th century.  After this date further inhumations occurred, but only at ERL104, for another hundred years until finally that cemetery too was abandoned in favour of a new site about 300m to the south. This new site was then utilised during the middle Anglo-Saxon period.  It has been estimated (Caruth & Hines, 2018) that the total burying population during the first phase, when all three cemeteries were in use, was 90-115 individuals but, in the second phase, when inhumations happened only at ERL104, the population had declined significantly to just 15-20 people. 

The Lakenheath 6 individual was interred during the first phase of burials in the West cemetery and his grave is identified in the archaeological reports as, ERL104 G294. This West cemetery is the largest of the three and, as already mentioned, the only one used throughout the early Anglo-Saxon period. It held 261 graves which were typically aligned east to west with a minority showing evidence of log coffin burial.  In their report (Cruth & Anderson, 2005) the archaeological team observed that "there is a general trend that suggests that the earlier burials are in the southern half of the site and that the area of burial extended northwards during the period of the cemetery’s use".  From published images of the grave plans I have not been able to identify the position of G294 with any confidence but, in the numbered plan of the ERL104 cemetery area (Figure 6, Cruth & Anderson, 2005), some twenty graves are identified within the G200-299 numbering sequence and all are grouped together in the north-eastern corner of the site so this perhaps is the area where Lakenheath 6 was buried (see Figure 3). 

Figure 3:  Plan of the West (ERL104) early Anglo-Saxon cemetery at RAF Lakenheath, Eriswell, Suffolk.  The red dashed circle indicates the area of the cemetery containing graves within the range G200-G299.  It seems to me possible that Lakenheath 6 may have been excavated from this area. (Plan illustration after that published in Caruth, J & Anderson, S., 2005) 

Remains of men, women and children were present in roughly equal proportions (Cruth & Anderson, 2005). The cemetery contained a variety of interesting mortuary practices including a warrior buried with his horse, several examples of young children buried with spears, several multiple inhumations and one grave in which a man was buried with a quiver of seven arrows. In three graves, G255, G221 & G313, putative musicians were buried each with a lyre (Caruth & Hines, 2018). Other grave goods included annular and cruciform brooches, glass and amber beads, wrist clasps, girdle hangers, shield bosses, knives and vessels. 

The burial of Lakenheath 6 (G294) is particularly noteworthy in that it is one of three graves of young adult males at Lakenheath that contain groupings of animal bone (Rainsford, 2017). The inclusion of animal remains was a routine aspect of Anglo-Saxon cremation rites and it sometimes also happened with inhumations during the early Anglo-Saxon period.  In both instances it is seen as an indication of probable pagan identity.  In burials G117, G294 and G443 animal bones of differing species are included; G117 includes cattle ribs, G294 contains a complete chicken and G443 contains sheep ribs.  In the G294 grave the chicken bones were placed above the mans' right shoulder beside his head.  So we can perhaps consider that, based on these burial rites Lakenheath 6 believed in a pre-Christian, pagan cosmology.  Another interesting characteristic of the Lakenheath 6 individual that is reported in the supplementary data published by Gretzinger et al.,(2022) is that he has an additional X chromosome and demonstrates the XXY kareotype associated with Klinefelter's syndrome.  Two other ancient DNA examples of Klinefelter's syndrome have recently been reported (Roca-Rada et al., 2022; Moilanen,et al.,2022). In modern populations the syndrome is reported at a frequency of around one in a thousand and is associated with above average height, learning difficulties and reduced fertility but the genotype may go unnoticed in perhaps a quarter of those effected (Anon, 2021). It is interesting to consider how Lakenheath 6 would have experienced his gender and how, if at all, this influenced his life and role in the Anglo-Saxon community at Eriswell.

Radio carbon dates from the grave of the warrior buried with his horse (G323), indicate that he was born circa 470CE and stable isotope analysis shows he grew up in the Lakenheath area.  This finding is typical for strontium and oxygen isotope results obtained from the Lakenheath skeletons where "the overwhelming majority of individuals had never moved more than 30 miles from where they were buried" (Caruth & Hines, 2018).  Hence we can conjecture that the Lakenheath 6 individual would have spent his life entirely within the locality surrounding the Lakenheath settlement and its cemeteries.  No radio carbon analysis has been performed on his skeleton but based on the position and cultural context in which he was excavated, his burial date estimate is 400-600CE (Gretzinger et al.,2022).  

So,"the material culture of the communities using the burial grounds [at Lakenheath] is entirely characteristic of Anglian England" (Hines, 2022) and stable isotope analysis confirms that most of those buried there were undoubtedly born and lived their lives in eastern England. Remains of the migrant founders of the community may have been among the earliest burials, possibly in some of the earliest cremations whose remnants are dispersed across the ERL104 site although, from the published reports, there is no evidence that any founder graves have been identified with certainty.  However, "both isotopic and genetic data yield a clear case for a substantial new population having settled here from across the North Sea from around the mid-5th century" (Hines, 2022). 

Table 1: Summary of fifteen samples from the three early Anglo-Saxon cemeteries at Lakenheath, Suffolk, England that were used in the study by Gretzinger et al.,2022.

Our understanding of the Anglo-Saxon migration into Suffolk, and its contribution to the early English gene pool, has been significantly expanded by NGS genome sequencing of 460 medieval skeletons excavated from across northwestern European (Gretzinger et al.,2022).  Fifteen of these samples came from the three Lakenheath cemeteries (seeTable 1). One individual came from each of the two smaller east and central cemeteries and thirteen were from the major west cemetery, ERL104.  In total the genomes of ten males from Eriswell were analysed and Lakenheath 6 was one of this group. In selecting the Lakenheath skeletons to be used "the principal criterion.....has been observable evidence suggesting close genetic relationship; eg. collocation in what look like family plots".    Based on their ancient DNA genome sequences the ancestry of all the individuals analysed from the Lakenheath cemeteries was primarily from the population that Gretzinger et al. have called Central Northern European (CNE).  They state that the emmigration source for this CNE population is that area we now refer to as Freisland, northern Germany, Denmark and southern Sweden (see Figure 4). From this, it seems to me reasonable to infer that the Y-chromosome lineages of the males buried at Lakenheath were also likely to have been present in this CNE geographic area at some time prior to the second half of the 5th century.  That is perhaps a generation or so before the earliest settlers were buried at Lakenheath.

Figure 4: Map showing the emmigration source (shaded red) for the Central Northern European (CNE) population in relation to the district of Tjust, Sweden (yellow circle), which is the seventeenth century ancestral origin of modern I-Y33765+,Swedish men. (Map after that published in Joscha Gretzinger,Twitter post dated, 21 September 2022)

At the present time, Lakenheath 6 is the earliest occurrence of any branch of the I-Y4252 clade whose mean formation date estimate is 13CE (95%CI, 325BCE-323CE).  In modern populations the I-Y4252 haplogroup has been reported throughout north western Europe, southern Scandinavia and the British Isles (see Figure 5).   So, it is possible that, within less than 500y of the formation of the I-Y4252 mutation, a male lineage of at least one of that clades branches, the ancestral line of Lakenheath 6, who we know to be derived for I-A19486, had enjoyed some proliferation within southern Scandinavia and then become part of a settler group that emmigrated and flourished in eastern England at the beginning of the Anglo-Saxon period.

 Figure 5: Distribution of I-Y4252 in modern Europe (source: Phylogeographer)

It seems to me that this straightfoward but dynamic narrative provides a helpful illustration of, and possible explanation for, the rapid expansion we see in the downstream phylogeny of I-Y4252.  In my previous post, I-Y33765 and other Baltic Sea branches of I-Y4252 , I speculated about changes and developments in Scandinavian society that may have contributed to a period of enhanced reproductive success for the earliest groups of men who were derived for the I-Y4252 mutation.  The glimpse we catch in our story of Lakenheath 6 and his direct-line male ancestors, is of a group of I-Y4252 men who were likely involved in some of those cultural developments. Certainly they must have been familiar with the dangers and advantages of travel by sea and the opportunities and hazards offered for their interactions with strangers and new places.  Two published studies have demonstrated that innovations in transport technology associated with migration and colonisation of new environments can produce fast expansion in dominant and priveledged male lineages that are seen as bursts of phylogenetic expansion in the Y-chromosome (Poznik et al., 2016; Balaresque et al., 2015).  I would argue that this is perhaps the case we observe with the quick development of so many branches below I-Y4252, where the development of the shallow draft, clinker built, iron rivet technology coincides with the migration of Germanic peoples outwards from southern Scandinavia.  Archaeological evidence for the origins of this revolutionary shipbuilding technique are found particularly in southern Sweden (Scania) and around the shores of the Danish archipelago.  In this south west corner of the Baltic these developments have been dated to the first half of the fourth century (Wolf, 2015).  Within a couple of centuries burials containing examples of complete ships or parts of such vessels are found from the province of Uppland in Sweden to the counties of Suffolk and Kent on the south-eastern corner of the British Isles (Brookes, 2007).  The archaeological context of these sites demonstrate how innovative Scandinavian ship design allowed communities bordering the Baltic and North Sea to interact with the early Anglo-Saxon settlements in eastern England including the community at Lakenheath.  

At the present time, the Lakenheath 6 individual is the closest ancient Y-DNA to our I-Y33765 clade with a TMRCA of around 1BCE according to the FTDNA Discover algorithm.  We know that he lived circa 500CE so that the founder of his migrant line likely arrived in Suffolk perhaps a generation or two before that date.  For the English arm of I-Y33765, I have speculated that our founder was a man from south eastern Sweden who arrived in England at about the time Cnut became king, so maybe circa 1020CE.  The proximity of the seventeenth century locus for the ancestry of modern Swedish I-Y33765 men in Tjust, Smaland, Sweden, (see Figure 4) would seem to imply our patriarchs community had some genetic affinity with the CNE population.  The migration from Scandinavia of both these men, although separated by half a millenium, was dependent on the seafaring culture and shipbuilding innovations that had developed in the south-western Baltic, particularly during the early iron age. My guess is that this unusually dynamic period would have given many opportunities for male reproductive success which fostered the genetic proliferation we see within the I-Y4252 haplogroup coincident with the Migration Period of the Germanic tribes.   

While writing this review, I have been very concious of the way in which our hobby has been transformed thanks to Next Generation Sequencing (NGS) technology. It will soon be the tenth anniversary of NGS becoming available as a direct-to-consumer, mass-market product.   This happened on 9th November 2013, when FamilyTreeDNA announced their BigY NGS test. I remember that then there was quite a flurry of speculation about how this new technology might benefit and increase the scope of "Citizen Science" genetic genealogy research.  The introductory offer price through to 31st November 2013 was $499 (£311) and  I was one of a group of five I-L233 "early adopters", all members of the I2a Y-haplogroup Project, who purchased the BigY test during that initial launch offer.  The four other chaps were Recker 246886, Lambert N20745, Fleming N10316 and Brown 4020. Our results eventually became available for us to download on 1st April 2014.  To any rational soul April Fools Day might seem quite an appropriate date on which to start puzzling about variants in vcf and BAM files. During the next few months, I am sure few of us hobbyists thought that within less than a decade we would be able to identify our Dark Age cousins and make TMRCA estimates with the precision now possible for Lakenheath 6 and his "brother" branches downstream of I-Y4252.  But this enormous benefit has only become possible because NGS produced great savings in the cost and time needed for whole genome academic research and because this revolution was so quickly then applied to many ancient genomes preserved in archaeological repositories and museams worldwide. It seems to me that the rate at which these studies of ancient population genetics have increased the number of archaeological samples for which we now have Y-haplogroup data is quite astonishing.  Even for our small "twigs" on the spreading Y-phylogenetic tree, the 2022 publication of the I-A19486 haplogroup assignment for Lakenheath 6 seems to open the possibility that perhaps, within the next ten years or maybe sooner, by some happy and whimsical chance, an archaeological sample with an I-Y33765 Y-haplogroup will been sequenced. Now that will be news worth writing about.

References

Anon (2021), Klinefelter Syndrome (XXY), Saint Mary's Hospital, Manchester Centre for Genomic Medicine, Manchester University NHS Foundation Trust, TIG 44/08, 5pp. 

Balaresque, P. et al. (2015) Y-chromosome descent clusters and male differential reproductive success: Young lineage expansions dominate Asian pastoral nomadic populations. European Journal of Human Genetics 23, 1413-1422

Brookes, S. (2007) Boat-rivets in Graves in pre-Viking Kent: Reassessing Anglo-Saxon Boat-burial Traditions. Medieval Archaeology 51, 1-18

Caruth, J & Anderson, S.(2005)  An assessment of the potential for analysis and publication for archaeological work carried out ar RAF Lakenheath between 1987 and June 2005. Vol1,
The Anglo-Saxon cemeteries ERL 104, ERL 046 and ERL 114. Suffolk C.C. Archaeological Service.

Caruth,J. & Hines, J. (2018), Excavations in the Anglo-Saxon Burial Grounds at RAF Lakenheath, Eriswell,Suffolk. A lecture given at the Society of Antiquaries of London, Burlington House, Piccadilly, 15 March,2018.https://www.youtube.com/watch?v=R9Q9yXir1gg

FTDNA (2023a), FamilyTreeDNA Y-DNA Haplotree https://www.familytreedna.com/public/y-dna-haplotree/I;name=I-Y4252 Retrieved, 1 May 2023

FTDNA (2023b), FamilyTreeDNA Discover Haplogroup Reports  https://discover.familytreedna.com/ Retrieved, 1 May 2023.

FTDNA (2023c), FamilyTreeDNA I2a Y-Haplogroup Project, DNA Results, Classic Chart https://www.familytreedna.com/public/I2aHapGroup?iframe=yresults Retrieved, 1 May 2023.

Gretzinger, J., Sayer, D., Justeau, P. et al., (2022) The Anglo-Saxon migration and the formation of the early English gene pool. Nature 610, 112–119. https://doi.org/10.103/s41586-022-05247-2

Hines, J (2022), A new Anglian community on the Suffolk Fen Edge: the sites at RAF Lakenheath.  Presentation given at the Society for Medieval Archaeology Annual Conference, "Current Perspectives on Early Medieval Migration, Mobility and material Culture", Oxford, 24-26 June 2022. 

Moilanen, U., Kirkinen, T., Saari, N-J. et al., (2022) A Woman with a Sword? - Weapon Grave at Suontaka Vestitorninmaki, Finland. European Journal of Archaeology 25, 42-60

Poznik, G.D. et al.  (2016) Punctuated bursts in human male demography inferred from 1244 worldwide Y-chromosome sequences. Nat. Genet. 48(6), 593-599

Rainsford, C.E (2017), Animals, Identity and Cosmology: Mortuary Practice in Early Medieval Eastern England.  PhD Thesis, School of Archaeological and Forensic Sciences, Faculty of Life Sciences, University of Bradford, UK

Rocca-Rada, X, Tereso, S, Rohrlach, A.B.et al., (2022) A 1000-year-old case of Klinefelter's sydrome diagnosed by integrating morphology, osteology, and genetics. The Lancet, 400, 691-692. 

Woolf, A. (2015) Sutton Hoo and Sweden Revisited In: The Long Seventh Century, Continuity and discontinuity in an age of transition. Ed.G.Alessandro. Peter Lang AG.