Exploring a coincidence -- Part 2:The cult of Clement in south west England

In the previous article I introduced the importance of the cult of St Clement for Viking dynasties during the eleventh century.  In England the cult seems to have had special significance in the half century between the accession of King Cnut and the Norman Conquest.  You may recall I have suggested that it was during this period the English I-Y33765 lineage originated from a Scandinavian man who was in some way involved with a cluster of seven north Somerset manors. In 1066 these manors were owned by four Scandinavian landowners, who were each characterized as “the Dane” by the scribe who compiled the Domesday record. So it seems the logical place to look for evidence of the cult of Clement would be in these manorial locations. For instance were any Anglo Scandinavian churches dedicated to the saint in these manors during the eleventh century?  The answer at first sight is sadly no.  All seven locations now have parish churches whose oldest surviving parts were built after the end of Anglo-Danish rule in England, sometime between 1100-1300, and whose dedications are to different saints none of whom are St Clement (see table).   

Church foundation dates and dedications in the seven parishes corresponding to the Scandinavian owned manors in north Somerset as recorded in Domesday

Indeed, medieval churches and chapels dedicated to St Clement, south west of the Thames, are very few (Crawford, 2008a, 2008b) (see map below). There are none in Somerset or Gloucestershire apart from the example in the city of Bristol. Here the chapel dedicated to St Clement is not relevant to our exploration because it was not founded until the end of the medieval period (see photograph below).  Consequently it is later than dates at which the Clement surname is already documented in north Somerset (circa 1303) and so had no influence on the popularity of the name. 

 Medieval churches dedicated to St Clement in the south-west of England.  St Clement, Powderham, Devon is in a manor owned by Tholf the Dane who also owned Tickenham in north Somerset.

Plaque on the site of the former Chapel of St Clement which stood in Princes Street near the quay in Bristol.  It seems this was not founded until the fifteenth century. 

A less obvious, but it seems to me, very significant link between the Somerset Scandinavian manors and St Clement is through the church dedicated to him at Powderham, near Exeter, Devon (see map above). From the Domesday record, in 1066, the manor of Powderham was owned by Tholf “the Dane” and importantly he also owned one of the seven north Somerset manors, namely Tickenham. 

Tholf was a substantial landowner in Wessex owning eighteen manors spread across five counties which were assessed at over 100 hides and worth £95 (see map).   

Wessex manors owned by Tholf the Dane in 1066

According to PASE (2020) the form of his name ”is characteristic of Denmark” and  “he was among the Danes settled in the heart of Wessex by the Danish kings of the earlier eleventh century”.  Among the Scandinavian owners of the north Somerset manors he is by far the wealthiest and the extent of his wealth would have given political influence.  Lewis (2016) classified Tholf as a “Great Landowner” and among this category “Tholf was the wealthiest great landowner whose property was confined to Wessex, with a value that made him almost as significant as any of the Danish magnates who had land there” and ”Tholf the Dane is likely to have been a first or at most second generation newcomer to Wessex”. In other words he was most probably a member of Cnut’s ruling Danish elite.  According to Crawford (2006) the hegemony of this group depended on trade and travel “Their lives were dominated by the sea and they needed a saintly protector to whom they could call- and to whom they could give thanks- for safe travel over water” “For this very reason the cult of Clement is likely to have played an important role in the daily activities of the king and his following”.      

While the present church at Powderham was not built until1258 it seems likely there had “been a little Saxon church on the site” (Anon, 2011) and Tholf’s political credentials make it entirely possible that this chapel would also have been dedicated to Clement.  After all the site on the banks of the Exe estuary in the “promontory reclaimed from the marsh” (Domesday Old English, 1086;  polra + hamm) would be entirely appropriate for a saint who preserved those threatened by water.  At the very least this connection between Powderham and Tickenham is useful circumstantial evidence that some of those “Danes” living in the Somerset manors had direct experience of St Clement and his cult. 

Also, three of the Scandinavian manors; Clevedon, Yatton and Tickenham were, during the Dark Ages, liable to frequent inundation from the Severn Estuary and all three may have had earlier churches associated with the sites of their later Norman buildings.  The dedications of these earlier churches were probably different from those used later so it is not impossible that one of these manors may have had an Anglo-Scandinavian church that was dedicated to Clement.  The very unusual dedication at Tickenham, to St Quincus & St Julietta, is of Norman origin and would definitely not have been the dedication of an earlier church on that site.  Barbara Crawford (2008a; 2008b) has noted that many churches originally dedicated to Clement were subsequently rededicated to other saints as the cult of St Clement became less popular (see St Nicholas, Bristol, below).

Manors owned by John the Dane in 1066. He was "Lord" in those shown with a light blue symbol.  One of these is Yatton in north Somerset.

The manors of Clevedon and Yatton were owned by John "the Dane".  Like Tholf he too was also classed by Lewis (2016) as a "Great Landowner" with 50 hides of land in seven manors across four shires of Wessex (Devon, Somerset, Dorset and Gloucestershire}.  According to PASE (2020) "His centre of operations may have been Yatton in Somerset, and there is some evidence of a connection with Bishop Giso of Wells (1060–88) (who acquired Yatton after 1066), through John’s probable son Northmann (fl. 1065–72). On balance John was probably the same person as John the sheriff who had an interest in a small estate across the Wye from Hereford and was probably sheriff of Herefordshire." From this biography we have another Scandinavian landowner in the north Somerset manors who seems to have been very much part of the Anglo-Scandinavian ruling elite.  The office of county sheriff was the highest official under the king in that county.  Also, because of our particular interest in church dedications it may be relevant that John has an unusual (for an eleventh century Dane resident in England) biblical name and that he may also have had a connection with the local Bishop.  Could this indicate a particularly devout family that would consequently be more inclined to found a church or chapel?  All the pre-Norman Conquest instances of the name John in Domesday refer to John "the Dane" and PASE (2020) notes  "It is almost as surprising to find it [John] as the name of a Danish layman as it would be of an Englishman". So maybe it was at John's Clevedon or Yatton manor that an early wooden church was dedicated to Clement.

As mentioned above, the port at Bristol was part of the Scandinavian trading network and a growing urban centre in the eleventh century. It had a chapel dedicated to Clement by the 15^th century but it seems rather strange there is no record of any such dedication before that date. This is the more so because of Barbara Crawford’s (2008a) description of a “typical” Clement church in England as follows; “it is the link with urban centres that is most striking” and a “strong association with the sea and with the Danish trading community” and “very often it is located at the end of the bridge or river crossing”. Taken together these criteria would seem to fit Bristol rather well and in particular one church site in the medieval port, that of St Nicholas which was by the city gate adjacent to the bridge (see map below) from which the settlement took its name (Domesday Old English, 1086;“Assembly place by the bridge”  brycg + stow).  The dedication here may be significant as St Clement’s role as patron saint for sailors and those traveling across water was superseded by that of St Nicholas after the enshrining of the latter’s relics at Bari, Italy in 1070 (Crawford, 2006).  So, as almost nothing is known about churches in Bristol prior to the Norman Conquest, it seems possible that a Saxon church on the site of the twelfth century Norman foundation dedicated to St Nicholas may well have been dedicated to Clement.  In this connection it is worth noting that Tholf’s manors at Tickenham and Powderham were 14.5km and 9km respectively from the significant Viking ports at Bristol and Exeter.  It has been suggested (Lewis,2016) that Tholf’s acquisition of these manors close to the two largest towns west of Winchester  “may well have been deliberate policy, and the manors may have been associated with urban property which was simply not recorded in Domesday book”. As Powderham and Exeter each contained a church dedicated to Clement perhaps if Tholf had trading interests through the port of Bristol he would have founded a chapel to that “sailors” saint at Tickenham too.

 

 

The Norman St Nicholas Church was founded in the 12th century and dedicated to St Nicholas as the patron saint of seafarers.  It stood at the northern end of Bristol bridge by the harbour and town gate.  It was on the route into Bristol for those coming from Somerset and from the Scandinavian manors.  Could an Anglo-Scandinavian chapel on this site have been dedicated to St Clement, the sailor's patron saint in the late Viking Age?

So it seems to me there are several reasons why we may surmise a connection between the cult of Clement and the Scandinavian manors of north Somerset.  Certainly two of the landowners had status and wealth that would make it feasible they may have founded a chapel to this Viking saint in the area.  But, even if that were so, how might this be connected with the association of St Clement's name with the I-Y33765 SNP?  Well, because it is a saint's name we should assume Clement was "chosen" or "bestowed" as a family name to honour the saint and aspects of his cult (Hanks & Hodges, 1988). Since this is the case perhaps, in the two centuries between 1066 and the end of the 12^th century, descendants of the I-Y33765 patriarch were inclined to adopt the saint’s name because of its perceived link with missionary zeal or with the Scandinavian Christianity of their ancestral line or perhaps with the protection Clement brought to those in peril at sea?   Implicit in this theory is the notion that these descendants and also their close community retained some awareness of their Scandinavian origins for perhaps eight generations.  While Anglo-Scandinavian personal names have been recorded in the south west of England during the Norman period (Higham, 2020) it is hard to judge the plausibility of such assumptions.  On the other hand, if there is no basis for my idea that some ancestral awareness motivated descendants of our patriarch, during the twelfth and thirteenth centuries, to adopt the Clement surname then the coincidence of their choice seems rather remarkable given the explicit Scandinavian context we have discovered for the St Clement cult.

Consequently it seems to me most plausible that the Clement surname, which is shared by English men who are derived for the I-Y33765 Y-DNA marker, became their hereditary family name precisely because it was the name of a saint honoured in the Anglo-Scandinavian communities in which their ancestors lived during the 11^th century.

References

Anon, (2011) St Clement's Church, Powderham 1259-2011, Powderham PPC 8pp

Crawford, B.E.(2006) The Cult of St Clement in Denmark, Historie, p235-282

Crawford, B.E (2008a) The Saint Clement dedications at Clementhorpe and Pontefract Castle: Anglo-Scandinavian or Norman?, in Myth, Rulership, Church and Charters: Essays in Honour of Nicholas Brooks Ed. Julia Barrow, Andrew Wareham, Ashgate Publishing, p 189-210 

Crawford, B.E (2008b) The Churches Dedicated to St. Clement in Medieval England. A Hagio-geography of the Seafarer´s Saint in 11th Century North Europe. St. Petersburg: Axioma, 237 pp.

Hanks, P. & Hodges, F.(1988) The Oxford Dictionary of Surnames, Oxford University Press

Highham, R. (2020) The Godwins,Towns and St Olaf Churches: Comital Investment in the Mid-11th Century, in The Land of the English Kin, Studies in Wessex & Anglo-Saxon England in honour of Professor Barabara Yorke, p467-513

Lewis, C.P. (2016) Danish Landowners in Wessex in 1066, in Danes in Wessex, Eds Ryan Lavelle & Simon Roffey, Oxbow Books, p 172-211

PASE (2020) Prosopography of Anglo Saxon England, http://www.pase.ac.uk/

Exploring a coincidence -- Part1:The cult of St Clement and Viking ruling elites

The conventional explanation for the origin of the Clement hereditary surname in England is that it developed from the personal name Clement which itself became adopted in the late Anglo-Saxon period because of the popularity of the early Christian saint, Clement (Reaney, 1967; Hanks & Hodges, 1988). To date in England the I-Y33765 mutation has only been confirmed in men with this surname whose direct-line male ancestry is from rural parishes surrounding the port city of Bristol. As I have discussed in earlier articles on this blog, the genetic evidence from four FTDNA Big Y tests suggests that the I-Y33765 SNP formed in southern Scandinavia during the first Viking age and was subsequently brought to England in the early eleventh century by a Swedish mercenary who was possibly in the service of Cnut the Great. In this article and in the next I want to explore why the English descendants of this Scandinavian Viking seem to have adopted the hagionym of a 1st century martyred Pope as their family name.  

  

 The martyrdom of Pope Clement, circa 100AD 

To begin I intend to give a summary of the Clement cult and it's significance for Viking ruling elites.  Early Christian records suggest Clement was the third Pope, and probably the only one appointed by St Peter.  He was martyred at the end of the first century by being thrown into the Sea of Azov, Crimea, tied to a ships anchor.  Here it is worth stressing that his exile from Rome to Crimea and his subsequent martyrdom were both results of his exceptional ability to convert pagans to Christianity which made him unpopular with the Roman authorities.  Almost eight centuries after his death, in 867-8, St Cyril and St Methodius brought the supposed remains of Clement to Rome where they were enshrined in the Basilica of San Clemente.   Because of the manner of his martyrdom St Clement became regarded as the patron of sailors and those in peril of drowning.

 

Interior of the Basilica San Clemente, Rome.  The saints supposed relics are enshrined under the high alter.  The inset image is of a Ukrainian coin minted in 2006.  It shows Prince Vladimir holding a model of his Tithe Church in which he enshrined relics of St Clement at Kiev. 

The next important element of the story is that in the late tenth and eleventh century the cult of St Clement became very influential among the ruling Viking elites in Ukraine, Norway, England and Denmark. 

This process began when Prince Vladimir of the Kievan Rus acquired other putative remains of St Clement from Crimea and housed these in 996 at his Tithe Church in Kiev (Garipzanov, 2013).  In this way Vladimir hoped to use the cult of St Clement to suggest the status of Kiev was on a par with that of Rome, by its possession and veneration of the remains of a Pope appointed by St Peter himself.  Vladimir may also have thought that Clement's proven missionary prowess might assist him with the conversion of his Slav subjects.  However in addition the Kievan rulers actions introduced the cult to Scandinavian Varangian (aka Viking) merchants and mercenaries who frequented his capital while journeying along the river network that connected the Baltic and Black Sea.   

The Norwegian ruling dynasty of Olaf Trygvasson and his grandson Olaf Haraldsson, who both had close connections with the Kievan Rus, in turn brought the cult to Norway (possibly with more supposed relics) by founding churches dedicated to St Clement at Olso (Liden, 2007) and at Trondheim. The remains of the wooden church at Trondheim were discovered and excavated in 2016 (see illustration).  Dendrochronology of surviving timbers has shown that trees used in the construction were felled in 1008-9AD.  

Excavation in 2016 of Church of St Clement, Trondheim, Norway (top) and remains of Church of St Clement, Oslo, Norway (bottom) 

Further, it seems likely that at about this time St Clement became more broadly identified with the newly Christian political elites across Scandinavia possibly because of the saint’s supposed ability to both achieve Christian conversion among pagans and to protect those traveling by water (Crawford, 2008a). Clearly these dual characteristics would make Clement an attractive guardian for any newly Christianized Viking whether he should be a humble mercenary or a mighty Sea King.

Olaf Haraldsson eventually became King of Norway in 1015 but his reign was ended in 1029 when Cnut the Great invaded his country.  Olaf escaped via Sweden and went into a short exile in Kiev but in 1030 was killed trying to regain his Norwegian throne at the Battle of Stiklestad.  He was subsequently declared a saint in 1164 and still has great significance for the Norwegian national identity.  

Church of St Jorgensbjerg, Roskilde, Denmark.  Originally dedicated to St Clement and dating from 1030-35 during the reign of Cnut the Great

It has been suggested (Crawford, 2006) that, as part of Cnut the Greats political struggle to control Norway, he decided to actively introduce the Clement cult, possibly from his English realm, into his Danish kingdom. This view seems particularly well supported by the early dedications to the saint at the churches founded in Lund and Roskilde. The date of the Roskilde Clement church can be estimated from a coin hoard probably deposited at its foundation.  The English, Danish and German coins in the hoard suggest the building was built around 1030 and so definitely during Cnut’s reign and concurrent with his Norwegian campaign. Hence this indicates that there was also a “battle” for St Clement patronage between Danish and Norwegian dynasties at a time of existential conflict.  Cnut's eventual military victory being proof that his claim had found favour with a martyred Pope and his desire to demonstrate this saintly approval underlines the importance of St Clement to these Scandinavian rulers and to their followers during the eleventh century.

The number of medieval churches dedicated to St Clement in Denmark, Norway, Sweden and England is also interesting in this regard.  In Denmark twenty six examples are known, in Norway six, Sweden just one (at Visby, Gotland) but in England nearly fifty (Crawford, 2006).  In a comprehensive ten year study of the cult of St Clement in Scandinavia and in England Barbara Crawford (2008b) has examined the hypothesis that the growth of the Clement cult in England was directly linked to the ruling Danish royal dynasty and its followers.  From her findings it does appear that some dedications can be linked to patronage by the Danish elite following Cnut’s accession to the English crown in 1016. This is another element of the cults history that is important for the speculations that follow.

At this point it seems to me, we can begin to see the possible significance of the coincidence which prompted this discussion.   Namely, that we have a group of English men who share a Viking age Y-DNA mutation, I-Y33765, that was brought from Scandinavia to England by a follower of the Danish ruling dynasty and now we have seen that this group of I-Y33765 men also share a surname, Clement, that originates  from the name of a saint whose cult was apparently popular with the aforementioned ruling elite.   There is little doubt that for both mutation and family name to be found in the south west of England supposedly linked by the eleventh century Anglo-Scandinavian ruling class is an intriguing coincidence but is it anything more? It seems to me that at the distance of a millennium this curiosity is an unexpected discovery that is well worth fuller exploration.

In the next article I intend to present some evidence for the cult of St Clement in the environs of eleventh century Bristol where I suspect our Scandinavian Y-DNA eventually became paired with the hagionym and produced our Clement family identity at sometime around the middle of the thirteenth century.   

References

Crawford, B.E.(2006) The Cult of St Clement in Denmark, Historie, p235-282

Crawford, B.E (2008a) The Saint Clement dedications at Clementhorpe and Pontefract Castle: Anglo-Scandinavian or Norman?, in Myth, Rulership, Church and Charters: Essays in Honour of Nicholas Brooks Ed. Julia Barrow, Andrew Wareham, Ashgate Publishing, p 189-210 

Crawford, B.E (2008b) The Churches Dedicated to St. Clement in Medieval England. A Hagio-geography of the Seafarer´s Saint in 11th Century North Europe. St. Petersburg: Axioma, 237 pp.

Garipzanov, I.H (2013) The Journey of St Clement’s Cult from the Black Sea to the
Baltic Region, in From Goths to Varangians. Communication and Cultural Exchange
between the Baltic and the Black Sea, Ed. Line Bjerg, John H. Lind, and Søren M.
Sindbæk, Aarhus University Press, p 369–80.  

Hanks, P. & Hodges, F.(1988) The Oxford Dictionary of Surnames, Oxford University Press

Liden, H-E (2007) The Church of St Clement in Oslo, in West over Sea. Studies in Scandinavian Sea‐Borne Expansion and Settlement  Before 1300.  A Festschrift in honour  of Dr Barbara E.Crawford , Ed. Beverley Ballin Smith, Simon Taylor and Gareth Wells, Leiden and Boston, Brill.  The Northern World, 31 p 251-2

Reaney,P.H.(1967) The Origin of English Surnames, Routledge & Kegan Paul, London

I-Y33765 draft tree October 2020

This is the latest draft tree for I-Y33765.  Some already identified SNPs on the English branch cannot be placed correctly at present until we have the result of the ongoing FTDNA Big Y-700 test for Clement IN82043.  Clement YS32045 is also awaiting a test result for Y33765 from YSeq and at present is only predicted as derived on the basis of his documented genealogy.

The STR genetic distances (GD) shown are correct across the entire chart based on the six 111STR results we have.  Dahlberg IN81271 has tested 37STR but his position in the chart is correct (he is confirmed derived for Y33765 at YSeq).  The more 111STR results that become available the more confident we can be in the GD relationships but, because STR markers can "back mutate", anomalies may become apparent due to the "convergence" artifact.  So far that does not seem to be an issue.

The dates included are based on YFull or FTDNA TiP estimates or on known dates from documented genealogy.  The estimated dates are only a very approximate guide to the age of branches and are most likely to have large errors.  The dates of branches will likely be revised in subsequent drafts; again as more SNP and STR results are added on descendant branches the reliability of shared dates may be improved.

Click on chart to enlarge.
 

I-Y33765 and early maritime culture in the Baltic

Four Swedish men with seventeenth or eighteenth century direct-line male ancestry from the harads of Tjust or Kinda, Småland are derived for the I-Y33765 SNP and share a varying number of downstream (more recent) mutations.  Apart from this genetic similarity there is no documented genealogical connection between these men.   The grouping of their four derived (+) results in such close proximity suggests that the Tjust region might be considered the ancestral "homeland" of the I-Y33765 clade.

The eastern boundary of Tjust is formed by the Baltic Sea and here it's coast is characterized by an archipelago with elongated bays, that at several places extend deep into the interior of the region.  Since the end of the last ice age there has been considerable geological "uplift" along much of the eastern seaboard of Sweden (Passe & Daniels, 2015) and in the area of Tjust since the Vendel period (AD550-800) this elevation of the shore level has been by two or three metres.  Hence, at the time the Y33765 mutation formed (circa 670AD), inlets, rivers and streams would have been navigable further inland.  During the Vendel and Viking periods the major bays of Gamleby Viken and Gudingen and the streams entering them would have provided perfect navigable access to the hinterland around the present day settlements of Gamleby & Lofta.

This was also the case during the early Iron Age and Bronze Age and the Tjust coast has many examples of Bronze age rock carvings that demonstrate the familiarity of those living there with boat building, sea faring and navigation.  At Casimirsborg in Gamleby parish in 2010 an outcrop of rock was discovered that shows one of the largest groups of Bronze Age ship images found anywhere in Scandinavia.  It contains representations of over a hundred engraved ships (Goldhahn, 2011).  When the images were made in the middle part of the Bronze Age the rock outcrop on which they are carved lay near the eastern shoreline of Gamleby Viken in a natural harbour (Broström, 2011).

Bronze age ships depicted in rock art at Carimirsborg, Gamleby parish, Tjust, Sweden

Similar rock art images of ships are found in other coastal areas across the Baltic and together these demonstrate that a maritime culture existed around its shores from an early date.  Archaeologists consider this shared culture reflects a Bronze Age coastal trading network.  A detailed study of the archaeology of this network (Wehlin, 2013) has identified Gamleby Viken as one of several "nodes" on the east coast of Sweden that connected the western Baltic to Gotland, Mälaren and the Gulf of Finland in the east (see map).  Wehlin terms this network of trade routes and shared maritime culture around the eastern Baltic as a "Maritorium".

Baltic trade routes.  The route along the east coast of Sweden, which connected the western Baltic to the Gulf of Finland was in use from the Bronze Age.  The extensive bays of Gamleby Viken and Gudingen are a strategic anchorage on this route, north of Oland and opposite Visby and facing the eastern Baltic (cross symbols show ancestral locations for I-Y33765  men)

It seems quite plausible that the technically advanced Bronze Age shipbuilding implicit in such an extensive network would develop into the robust and innovative Scandinavian ship technology of the Iron Age based on broad, shallow drafted, lapstrake hulls (clinker boarded), in which the strakes (boards) were joined together with iron nails riveted through iron roves (washers), and masts with a single rectangular sail.  This sophisticated Scandinavian ship building revolution allowed "Northmen" from Denmark, Norway and Sweden to trade, pillage and explore into distant seas and rivers of the then known world. In the Baltic many of the trading routes that were established in the Bronze Age persist through to the late Viking Age and beyond (see map above).  So for centuries this maritime network would have distributed the genetics of Scandinavian coastal communities, along with their produce and goods, throughout the inland sea and beyond. 

The essence of Iron Age Scandinavian ship technology: a handmade iron ship rivet and rove washer (left); ship rivets from the Sutton Hoo ship burial (middle); ship rivets joining the strakes on the Nydam iron age boat (right).

Clear archaeological evidence that this Iron Age maritime culture was active in the Gamleby district contemporary with the formation of the I-Y33765 SNP has already been recorded. The cremation boat burial at Gunnerstad contained iron ship rivets indicating that the boat used was of clinker boarded design and the scorching of stones within the mound suggested it's length was about 5m.  This size would make it suitable for rivers and protected routes following the coastline. The burial has been dated to the beginning of the 6th century AD (Palm, 2017) during the Vendel Period and at that date such a craft may have just had oars rather than a mast and rectangular sail   Also, between the bay of Gamleby Viken and the inland waters of  Dynestadsjön the remains of a Viking period “pole barrage” has been radio-carbon dated to 1030 +/- 30ybp. (Palm & Rönnby. 2018).  The structure is submerged within the narrow channel of Dynestadviken at a place called Stäket.  Archaeological surveys of the site are ongoing but marine archaeologist Johan Rönnby of  Södertörn University / MARIS has said "I would not be surprised if there is a Viking ship down there somewhere because it was quite common to use old boats when constructing pole blockages".  At the Skuldelev defensive blockage in the Roskilde Fjord, Denmark, six old ships were sunk for this purpose between 1070 and 1140AD. These Skuldelev wrecks were excavated by Danish archaeologists in the late 1950's.  The pole blockage at Stäket probably indicates that the Dynestadsjön pool was used as a harbour during the Viking Age. If so, this is evidence that the hinterland of the nearby Husa "central place" was connected to the Baltic trading network at this time.

Within the past month the result of a major, six year study into the population genomics of the Viking World has been published.  The authors (Margaryan et al., 2020) extracted genomic DNA from 442 ancient humans, mostly from Viking age burials (142 Viking age samples from Sweden) and compared them with genomic samples from modern populations.  Their findings confirmed previous conclusions based on medieval documentary sources and on archaeology; that Vikings with Danish ancestry mainly moved west to England, those with Norwegian ancestry traveled to Iceland, Greenland, Ireland and the Isle of Man, while the eastward expansion and exploration of the rivers of Russia and eastern Europe involved Vikings who were mainly from Sweden.  However they noted "we also see evidence of individuals with ancient Swedish and Finnish ancestry in the westernmost fringes of Europe".  This comment seems compatible with the evidence available from present results for the I-Y33765 clade which appears to have migrated from south eastern Sweden to south western England. These authors also report that in most of Viking Age Scandinavia the distinct regional populations show little or no evidence of genetic mixing.  However they found greater genetic diversity in "a few cosmopolitan centers to the south" in southern Sweden (notably Oland and Gotland) and Denmark.  They interpret this as being "consistent with a limited number of sea routes between different Scandinavian areas and beyond".  

Just how to estimate when I-Y33765 is most likely to have made its journey from Scandinavia to England is an interesting puzzle. As mentioned earlier, historic sources and archaeology strongly suggest that earlier Swedish Viking voyages both for trade or plunder were typically to the east. Maritime trade routes connected to Tjust would seem to facilitate travel in that direction.  Consequently, it does not seem unreasonable to conjecture that, as the I-Y33765 SNP formed circa 670AD, during the three hundred years following its formation any chap carrying that mutation would naturally seek his fortune to the east. Hence it maybe that in the future, when more men have their Y-DNA tested, descendant lineages of I-Y33765 will be identified in Estonia, Belarus or Ukraine.  

Rune stone Sm101 in the parish of Nävelsjö, Småland: The runic inscription is translated as "Gunnkel placed this stone in memory of Gunnar, his father, Rode's son. Helge laid him, his brother, in a stone coffin in Bath in England".  Sweyn Forkbeard's followers were at Bath, Somerset in 1013.

It was only when the flow of silver dirhams from the Middle East decreased in the latter quarter of the tenth century that Swedish adventurers began to look elsewhere for opportunities and, as a result, joined the ambitious Danish kings on their manoeuvres to the west,  in England. Although rune stones are not dated, the majority of those in Sweden that refer to men who traveled to, or who died in, England seem to relate to the period at the very end of the 10th and beginning of the 11th centuries when English silver geld payments were at their maximum.  It seems to me very likely that during these few years or the decades immediately after, between say Sweyn Forkbeards first attacks on England in the early 990's and his grandson Hathacnut's death in 1042, the I-Y33765 haplogroup somehow "found it's way" from Tjust to north Somerset.   And as evidence that this may not be too fanciful an idea a Viking Age rune stone in Småland, in the parish of Nävelsjö (Sm101), is a memorial to a man named Gunnar who made almost exactly the same journey during that period. He died and "Helge laid him, his brother, in a stone coffin in Bath in England".  Nävelsjö is about 100km south west from Tjust and the city of Bath is in north Somerset about 15km east of the parishes where the ancestors of our English I-Y33765 men were living in the eighteenth century. 

References

Broström, S.G. (2011) Skålgropsfat, skeppshäll och solvagn : nyfunna hällbilder vid Casimirsborg i Tjust vid norra Smålandskusten, Fornvännen, Journal of Swedish Antiquarian Research, 106, 54-57

Goldhahn, J. (2011) Törnsfall 107 – hällbilder vid ett röse och ett röse med hällbilder, Kalmar Studies in Archaeology VIII, Linnéuniversitetet, Kalmar

Margaryan, A., Lawson, D., Sikora, M. et al. (2020) Population genomics of the Viking world. Nature 585, 390-396 

Palm,V., Rönnby,J. (2018) Stäket vid Valstad, Gamleby socken, Stiftelsen Västerviks museum

Passe, T., Daniels, J. (2015) Past shore-level and sea-level displacements, Geological Survey of Sweden

Wehlin, J. (2013)  Östersjöns skeppssättningar - monument och mötesplatser under yngre bronsålder,  GOTARC Serie B. Gothenburg Archaeological Theses 59