Haplogroup I-Z63

• 1. Introduction

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  Haplogroup I-Z63 links a United States president, a Scottish noble clan, and a Mayflower pilgrim. All three trace to a single man believed to have lived in ancient Jutland around 2500 BCE. That ancestor's Y chromosome has since appeared in a possible Kievan prince's grave and in a late Roman excavation in Rome. It has also been found in warrior burials across Poland, Italy, and Hungary. The one place where this lineage is strikingly sparse today is modern Denmark, the very peninsula where it is thought to have begun. By the year 945, King Hacon of Norway arrived in Jutland and slew many of its people. He drove the survivors, as one source puts it, far up into the land.

• 2. The Jutland Paradox

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  YFull, a company specializing in Y-DNA analysis, estimated that I-Z63 formed approximately 4,600 years ago, around 2600 BCE. Their estimate carries a 95 percent confidence interval of 5,100-4,000 years before the present. The time to the most recent common ancestor was placed at 4,400 years ago. That figure carries its own confidence interval of 4,900-3,900 years before the present.

  The earliest physical evidence for I-Z63 comes from a Danish peat bog site called Hestehavens Mose, near the town of Hjørring. The individual there, catalogued as CGG106524, was dated by carbon-14 analysis to approximately 2,275 years before the present. That places the burial in the pre-Roman Iron Age, roughly 400-220 BCE. The haplogroup assigned was I1a3a1a2a1b1a, designated PH3482 or Y7627. That subclade sits within the I-BY316 branch of I-Z63. YFull estimates PH3482 formed around 2,800 years before the present.

  Just south of the Jutland peninsula, in the German city of Schleswig, a separate I-Z63 individual was found at the Rathausmarkt excavation. Sample SWG007, taken from grave 179, dated to 1070-1140 CE. Schleswig stands on the site of Hedeby, a major Viking settlement destroyed in 1066.

  The combined evidence supports a working hypothesis placing the progenitor of I-Z63 in ancient Jutland around 2000 BCE. In the modern world, the strongest concentration of I-Z63 lies not in Denmark but in the British Isles, Finland, Norway, Sweden, and Aland. Researchers have traced the near-absence from Denmark to migrations outward and repeated displacement of the original population by outside groups over many centuries.

  One of the haplogroup's diagnostic markers is a value called DYS456, which typically reads below 15 in I-Z63 carriers, though individual exceptions exist.

• 3. The Gothic Trail

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  In 2017, Polish researchers assigned Y-DNA haplogroups to 16 individuals excavated from Kowalewko. Three of those 16 belonged to haplogroup I-Z63, specifically the subclade I-L1237. Kowalewko has long been associated with the Wielbark culture. Scholars have in turn linked the Wielbark culture to the Gothic tribe of late antiquity. That makes I-L1237 one of the few genetic markers plausibly traceable to Gothic ancestry through ancient DNA.

  An academic theory known as the Jutish Hypothesis proposes a link between Gothic migration patterns and early British settlement. The hypothesis draws support from medieval texts. Asser, writing in his Life of Alfred in 893, identified the Jutes with the Goths. He connected that identification to a genealogy: Alfred the Great descended, through his mother Osburga, from the ruling dynasty of the Jutish kingdom of Wihtwara. Wihtwara was located on the Isle of Wight. The 13th-century Gutasaga adds another thread, recording that some inhabitants of Gotland left for mainland Europe. Burial sites discovered in the 19th century near Willenberg, Prussia, now the town of Wielbark in Poland, are attributable to either Goths or Gepids.

  The Jutes invaded and settled in southern Britain in the late 4th century, part of a broader wave of Germanic settlement. Under the Jutish Hypothesis, British and Gothic migration patterns represent two expressions of the same demographic shift. The genetic record appears to preserve traces of that shift.

  In a late 6th-century cemetery in Collegno, near Torino, a burial associated with Gothic and Lombard remains yielded sample CL63. The individual was an autosomal outlier at the site, possibly accepted into a kinship group while living far from home. CL63's subclade, I-FT104588, matches a Visigoth sample called I41203 found in Bulgaria. One hypothesis links CL63 to the deposed Visigoth King Suintila, supported by carbon-dated timelines, ancient DNA, and Y-DNA data. The genealogical thread extends further. A lineage thought to descend from Suintila's surviving son re-emerges in Burgheim by 1290 CE under the surname Swend. In 1604, a later member of this line claimed ancient Roman status from the German emperor Rudolf II through the scholar Dr. Johann Wilhelm Ganzhorn. Imperial recognition was granted, and a surviving letter of protection signed by the emperor has been preserved.

  At Rome's Crypta Balbi site, a burial dated to 400-600 CE yielded an individual carrying haplogroup I-Y7234. Lombard-associated ornaments were excavated at the same site. Five of the seven individuals there, including the I-Z63 carrier, clustered with central and northern Europeans in a ChromoPainter analysis.

  Tiszafüred 798, found at Majoros-halom in Hungary, belonged to the Late Avar cultural group and lived between 700-800 CE. Tiszafüred 509 lived between 800-830 CE. Both carried haplogroup I-S10360. Avars under a khagan called Bayan, in 565 AD, allied with the Lombards and defeated the Germanic Gepids in the Danube Plains. One explanation for I-Z63's presence in Avar burials lies in these alliances. The Avars helped the Lombard king Grimoald defeat a rebellion in Frioul in 663 AD. A third Hungarian individual, Magyarhomorog 88, from the Kónyadomb area in Magyarhomorog, belonged to subclade Y2245/PR683 and lived between 1000-1100 CE.

  While the Goths and Avars carried I-Z63 through central Europe, a separate branch of the lineage was moving into Scandinavian and Kievan circles. One of its carriers may have been a prince of Kiev.

• 4. A Kievan Warrior

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  Bodzia Cemetery in Poland held a burial dated to approximately 1010-1020 AD. The grave goods pointed unmistakably to a connection with the Kievan Rus ruling elite. The individual, catalogued as VK157 or burial E864/I, carried haplogroup I-Z63, specifically the subclade I-S2077. Strontium analysis of his tooth enamel showed he was not local to the area. He is thought to have come to Poland with the Kievan prince Sviatopolk the Accursed, a son of Vladimir the Great. Sviatopolk was married to a daughter of the Polish king Boleslaw the Great, known in Scandinavian sources as Burisleifr.

  VK157 was not a simple retinue warrior. His burial was the richest in the entire Bodzia Cemetery. Scholars note that in 1018, Sviatopolk retreated from Kiev to Poland and then vanished from the historical record. Given the burial's timeline and the richness of the grave, some researchers cannot exclude the possibility that VK157 was Sviatopolk himself. The identification remains speculative. The genealogy of the Rurikid dynasty at this period is fragmentary, and birth dates for many princes are only approximate.

  A second sample possibly linked to Kievan expansion was found in a region now known as Zeytinliada, in Erdek, Turkey. The individual, aged roughly 25-35, lived between 600-1000 CE. This sample belongs to subclade I-Y3979. Its genetic profile does not resemble northern Europeans. One interpretation suggests the individual descended from a northern European who intermarried with the local population. That ancestor may have served in the Varangian Guard of Byzantium. The Kievan Rus provided the earliest members of the Varangian Guard, entering Byzantine service as early as 874.

  An unpublished Stockholm University study of a Viking Age site on Gotland, a Swedish island in the Baltic Sea, references 6 samples of haplogroup I-Z63. All 6 belong to subclade I-BY316, specifically branch I-FT140572, which formed around 350 BCE. Preliminary analysis by FamilyTree DNA suggests 5 of the samples share 2 new SNPs, forming a branch designated I-FTJ74. The 6th sample lacks coverage for those mutations.

  VK157 carries a specific genetic marker, a SNP designated 300756, unique to the I-Y45113 branch of I-Z63. That marker places this possible Kievan prince within the same broader haplogroup. Centuries later, it would appear in a Scottish noble clan and a United States presidential lineage.

• 5. Clans and Presidents

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  Clan Hamilton, one of the prominent Lowland Scottish clans, traces its documented founding to Walter fitz Gilbert of Hambledon in 14th-century Lanarkshire. The Hamilton DNA Project has involved hundreds of participants, including a close relative of the current Duke of Abercorn.

  Results show that all branches descending from Sir James Hamilton, 5th Laird of Cadzow, belong to haplogroup I1-Z63. One branch accumulated titles running from Laird of Cadzow to Earl of Arran, Marquess of Hamilton, and Duke of Hamilton. That dukedom passed to Clan Douglas in 1895 when the 12th Duke of Hamilton died without a male heir. A separate branch ascended through Lords Paisley, Earls and Marquesses of Abercorn, to Dukes of Abercorn, a title that continues today. Genetic analysis suggests all these lines share a most recent common ancestor who lived roughly 750 years ago.

  Chester A. Arthur, born in 1829 and the 21st president of the United States, is believed to belong to haplogroup I1-Z63. Results from the Arthur family DNA project place his lineage in the branch I1-Z63 > BY151 > BY351. Arthur died in 1886.

  William Bradford, the Mayflower passenger who led the Plymouth Colony, is represented in I-Z63 by at least two tested descendants. Both fall under the subclade chain I-Y21381 > Y21371 > Y21370 > Y21372 > FGC72882.

  Richard Bradberry, of King William County, Virginia, is considered the common ancestor of a cluster of I-Z63 individuals. He was born around 1775 and died around 1826.

  The Bradford lineage sits at subclade FGC72882 within I-Z63. That chain of tested descent connects a Mayflower passenger to a Y-chromosome lineage whose earliest known trace sits in a peat bog near Hjørring, Denmark.