Summary of Previous Thys Barentsen Post

This post is a brief summary of the contents of the long blog I posted on 3-30-2020 regarding Thys Barentsen's Ancestry. Since few peple are even remotely interested in the subject of Swaim genealogy, and most who are probably don't want to spend more than a few minutes reading about it, this post will provide the basics of my investigation into Thys Barentsen's ancestry based on my Y chromosome DNA results. Anyone interested in more detail may then read the longer blog if they choose.

Although the story of my investigation is specifically about the search for Thys Barentsen's ancestors, it is also more generally a story of how Y-chromosome DNA matching enabled one amateur genealogist to solve a genealogical puzzle that had for decades eluded previous researchers.

My Original Purpose in Testing my Y Chromosome DNA

I had been using 23andMe, My Heritage, Family Search, and Ancestry to build my family tree for about two years before I considered testing my Y-DNA. I was confident that I already knew my paternal line ancestry up to Thys Barentsen, who immigrated to America from the town of Leerdam in the Netherlands in 1661 and who was generally considered to have been born in 1621 (this date is apparently based on a statement made by Thys Barentsen in New Amsterdam, rather than a birth or baptism document).

Thys Barentsen's parents and ancestry beyond his parents is provided in various family trees available online, but there has never been any convincing evidence that this ancestry is accurate. According to some of this purported information, Thys Barentsen's father was named “Barent Thys Barentsen,” “Barent Swaem,” “Barent Barentsen van Rottmer,” and so on. His mother was supposedly “Sibilla Unknown” or “Sibilla Verwaaijen.” His paternal grandparents were supposedly “Barent van Rottmer” and “Geesje Barents,” one or both of them having been born in what is now northern Germany. Some purported ancestries go further back, into a line of people surnamed “van Roest” or “van der Roest,” going back to a “Jan Baptist van Roest” born in 1400 in Schleswig-Holstein.

I knew that some of the more serious researchers were skeptical of these ancestries, but there were some signs here and there that there might be some truth to them. I have many DNA matches in Ancestry.com who have Annetie Barents van Rottmers, wife of Albert “de Norman” Bradt, in their family trees, and Annetie was supposedly the sister of Barent Barentsen van Rottmer. On MyHeritage.com I have a DNA match who lives in the Netherlands and has in her tree an “Albarta Hendrika van Roest” born in the 1800's who lived in Renkum, Gelderland, and had a daughter named Sibilla. Albarta could be a descendant of the van Roest familly who had remained in the Netherlands, and based on this and other indications, it seemed possible that these purported ancestries had some truth to them.

But still, Thys Barentsen was just one ancestor of more than 300 who had immigrated to America from Europe (most of them in my father's line), and just one of 2,048 who were my 11th-generation ancestors. The paternal line is special, however, because Y-DNA is passed down only through that line, and also because in modern western socieites the family name is passed down in a way that mimics how Y-DNA in is passed down. Bur working out Thys Barentsen's ancestry in the Netherlands might be difficult, in part because in the 1600's the Netherlands still used the patryonymic naming system rather than a surname system, and the Swaim named had apparently been only used beginningn with Thys Barentsen's children. Thys Barentsen himself apparently had not used the name “Swaim,” and his ancestors probably hadn't, either. Some families in the Netherlands at this time, however, did use a surname, although these familes were often noble families and I had no information to indicate that Thys Barentsen had descended from such a family.

But I also had some nagging doubt that Thys Barentsen was even my ancestor. This doubt existed for two reasons. The first reason was because when I searched on the name “Swaim” in Ancestry's “Surname in matches' trees” feature, I only came up with 18 matches who had that name in their family tree. This isn't many at all, particularly given the fact that the Swaims in general had been prett prolific down the generations, so that I should have thousands of DNA matches. Only a fraction of those would have had their DNA tested, of course, but still it seemed too few.

The second reason I had some doubt that I was a Swaim was because my surname was actually “Swain,” not “Swaim,” ending with an “n” rather than an “m.” Since there was more than one line of Swains who had immigrated to America from England in the 1600's, it was possible that I was actually a Swain rather than a Swaim. And, to support this possibility, I had 80 DNA matches in Ancestry with a Swain in their tree. Also, all but 1 of these 80 matches was a distant cousin and therefore did not have my immediate family or my first cousins in their family trees (this was important because the genealogical record showed that the family name had been changed from Swaim to Swain with my father's father. This means that only 1 of the 80 Swains (a daughter of my father's brother) was descended from the grandfather with the surname change.

So although my family tree showed that I should be a Swaim, the autosomal DNA was puzzling.
80 Swains but only 18 Swaims! Maybe I really was a Swain whose paternal line descended from England, rather than a Swaim whose paternal line descended from the Netherlands through Thys Barentsen.

Thus, I finally decided to test my Y-DNA to settle this question once and for all. I want to make clear that Y-DNA testing will not clear up such issues for many people, because as with all DNA testing, establishing relationships based on Y-DNA testing relies on matching your results with those of other people, and if none of your relatives has taken the test, then taking the test may establish nothing. However, I knew that in my case I would be able to definitely settle the issue of whether or not I was a Swaim because I knew that a couple dozen Swaims, relatives of Thys Barentsen, had already tested their Y-DNA with Family Tree DNA (FTDNA). Many of them had tested their Y-DNA as early as 2007 as part of the Swaim Surname Project, which had been organized by Laraine Clark and Lloyd Swaim in order to resolve the issue of whether the Swaim line had branched off the van Pelt line, as some believed, or whether the Swaim line was independent of the van Pelt line. Y-DNA testing had settled that issue in 2007 by proving that the Swaim line and the van Pelt line were two separate lineages. The project results were still useful, however, as it provides a database of Swaim Y-DNA to test against. If my Y-DNA matched Swaim Y-DNA, then this wold be definitive proof that I was descended from Thys Barentsen; if it did not match, then I was not descended from Thys Barentsen and I would have to revise that entire line of my family tree.

FTDNA sells three different levels of Y-DNA STR testing as well as various levels of Y-DNA SNP testing. SNP testing is ineresting in a scientific sense, but is not at this time highly useful for purposes of genealogy. For genealogical purposes, STR testing can be highly useful as it mutates at a slow but not too-slow rate, allowing relationships to be established based on degree of closeness of the tested SNPs.

My only question now was what level of STR testing I would pay for, as, naturally the cost of testing was higher as more STRs were tested. Also, it appeared that although accuracy of results might be somewhat increased as more STRs were tested, in most cases the increased accuracy of the higher levels would only be marginal. This is true because the STRs that Ancestry tests at the lower levels are not random, but are the STRs that mutate the most rapidly and thus are the most useful for genetic genealogy.

In the end I opted for the lowest level that FTDNA now tests for, which was Y-DNA37, meaning that 37 STRs would tested and matched against others in the database. I could always upgrade to a higher testing level (Y-DNA67 or Y-DNA 111) if the results at the lower level indicated that further testing might be useful. Since my purpose was only to determine whether or not I was a Swaim, and also since few of the Swaims had tested at a level higher than Y-DNA37, I saw no need to choose one of the more expensive testing levels. If I was a Swaim, I would learn that at the STR37 level.

I ordered my kit, swabbed my cheeks, and mailed the test back to FTDNA.

My Y-DNA Results

My results came within a few weeks and showed that my Y-DNA matched all of the Swaims in the FTDNA database, meaning that I was in fact a Swaim and a descendant of Thys Barentsen of the Netherlands.

The reason that I have so few Swaim matches in the Ancestry autosomal DNA database is probably that I probably don't carry any segments of autosomal DNA that are identifiable as “Swaim” DNA. This is not surprising, as the last common ancestor of the Swaims (Thys Barentsen) lived 11 generations ago for me, and autosomal DNA often is not useful to establish matches for a common ancestor that many generations ago, as autosomal DNA is chopped up at every generation through recombination. Furthermore, apparently nobody carries DNA from each of the 2,048 ancestors who had lived 11 generations ago, but only from a random selection of those 2,048 ancestors. It was very possible (in fact, likely), that I did not carry any autosomal DNA that was identifiably “Swaim” DNA.

My Y-DNA results were also interesting in a way that I didn't anticipate. They not only proved hat I was a Swaim, they also proved that other people with surnames other than Swaim were actually related through Y-DNA to the Swaims. Two of these Y-DNA matches were particularly interesting because they shared similar surnames that were obviously just variants of one surname, and also because this surname was obviously Dutch in derivation. The surname of one of these matches was DenHartog, the other Den Hertog; for convenience I will refer to all people with variations of this name (including Hertoch, Hartogh, Hertich, etc.) as “den Hartog.” Even more interesting, I was more closely related through Y-DNA to these two matches than I was to most of the Swaims! FTDNA describes the degree of closeness as “Genetic Distance,” which is simply the total number of STRs that that don't match; thus, the lower the number, the closer the distance. My results showed at the 37 STR level that I was related to DenHartog at a Genetic Distance of 1 and to Den Hertog at a Genetic Distance of 2. I was only related to one other Swaim at a Genetic Distance of 1, and to 3 other Swaims at a Genetic Distance of 2. I was related to 10 Swaims at a Genetic Distance of 3, and to 9 Swaims at a Genetic Distance of 4. FTDNA doesn't report matches at the 37 STR level with a greater Genetic Distance because it has determined that those matches are too distantly related to useful to the client (I disagree and would like more distant matches to be available for inspection, but that's a digression).

What this means is that the Swaims and the den Hartogs definitely share a common ancestor, and that this ancestor probably existed not too many generations above that of Thys Barentsen. This was entirely new information to me and was potentially very valuable in establishing Thys Barentsen's ancestry. We did not have an accurate family tree for the Swaims at a level above that of Thys Barentsen, but if the den Hartogs had a family tree that went that far back into the past it might be possible to work out Thys Barentsen's ancestry. This was because the Swaim family tree and the den Hartog family tree must merge to become the same family tree at the level of our last common ancestor.

FTDNA provides a “Profile” in which a match may include some personal information, and from this information and from an internet search it was possible to determine that DenHartog probably lived in Iowa and that Den Hertog lived in the Netherlands and that some of his paternal ancestors had lived in Utrecht. I also had an autosomal DNA match who descended from a line of den Hartogs who had immigrated to Iowa in 1847 as part of an organized religious emigration from the Netherlands. Her paternal immigrant ancestor was Dirk den Hartog (1818-1851), but because she descended from one of Dirk's daughters, the DNA of her male relatives would not be Swaim Y-DNA. However, Dirk den Hartog had emigrated from the village of Hei- en Boeicop, which is located about 5 miles from Leerdam. Since Leerdam is the town that Thys Barentsen had supposedly emigrated from, it was highly likely that this autosomal DNA match was related to me through a common ancestor of the Swaims and den Hartogs (however, it is likely that some or all of the 3 segments of DNA that we share is not actually “Swaim” DNA, as we also have more recent ancestry in common from some of the same areas in Norway and Sweden).

I also searched for and found online (Geni.com, FamilySearch.org, etc.) family trees for the den Hartog line, including the descendants and ancestors of Dirk den Hartog, going back to the Middle Ages in the Netherlands to the Lords of Arkel, who were a powerful dynasty in the region of Leerdam called the Land of Arkel (which has a lot of overlap with the region of Vijfheerenlanden). The Swaim Y-DNA match DenHartog is almost certainly descended from Dirk den Hartog's only son Jan Den Hartog.

My Strategy Based on the Y-DNA results and on den Hartog Family Tree Information

Now that my Swaim ancestry had been proved, my interest in Y-DNA shifted to exploring the relationship between the Swaims and the den Hartogs. My goal was now to identify the last common ancestor of the Swaims and den Hartogs and then work down the Swaim branch from that commn acnestor to locate Thys Barentsen. In reality, these were one thing rather than two, since I could only identify the common ancesor if I could connect him to Thys Barentsen.

Y-DNA matching can only do two things: it can prove that two people have a common ancestor and it can estimate the approximate generation of the last common ancestor of those two people. It cannot tell us the name, the geographical location, or any other information about that common ancestor; for that, we must rely upon traditional sources of genealogical information. Finding useful documentation from the 1400's, 1500's, and 1600's is a matter of luck, but fortunately some records from this far back do exist for various areas of the Netherlands, particularly baptismal, court, and land-transfer records. Furthermore, many Dutch individuals are interested in genealogy and have already organized much of this information, and Dtuch genealogies and forums discussing genalogies, are available online. This information is usually available only in the Dutch language, but Google Translate can provide a rough approximation of the meaning of what is being said, and often a closer examination of the translation against the orginal Dutch language can clarify a sentence of uncertain meaning.

Before proceeding further I first upgraded my Y-DNA test results to the Y-DNA111 level. DenHartog had tested at the Y-DNA67 level, and I wanted to see how closely we matched at this higher level. I decided to upgrade to the higher Y-DNA111 level, however, because two other matches (one of them with the surname Miller) had tested at the Y-DNA111 level and I wanted to see if and how closely we matched at that level. Also, there was the possibility that other matches might show up at the Y-DNA111 level that did not show up at the lower levels because our matching DNA was “back-loaded,” so to speak, meaning that the matching STRs were more concentrated in the last group or two of tested STRs than in the first group of tested STRs. Also, some future matches will certainly test at the Y-DNA111 level, and if I tested to that level now I wouldn't have to bother with upgrading to it in the future.

Unsurprisingly, I did still match closely to DenHartog at the Y-DNA67 level. Also, a new match did appear at the Y-DNA67 level who was not at the Y-DNA37 level, but he remains a mystery to perhaps be solved at some future point. Also, I was still a match at the Y-DNA111 level to both of the Y-DNA37 matches who tested at the Y-DNA111 level. This means that the match named Miller is closely related to the Swaims and den Hartogs; a possible explanation for this is provided in the longer blog post. 

To determine the probable generation of the last common ancestor for any two matches, FTDNA provides a tool it calls a “TiP Calculator.” I used this tool for the Y-DNA37 level for both DenHartog and den Hertog, and the calculation predicted that the last common ancestor of the Swaims and den Hartogs lived 15 generations in the past, with a probability of 99%. This figure was derived by using the “unrefined” calculation rather than the “refined” calculation. In this summary I won't discuss the difference between the refined and unrefined calculations, but I had determined that the unrefined results were probably more accurate than the refined results, based on the results I had obtained from determining the last common ancestor of the Swaims for whom I already knew the last common ancestor (all Swaims descend from Thys Barentsen, but some will have a more recent common ancestor than Thys Barentsen because they descend from different sons and grandsons of his). The refined results for the Swaims and den Hartogs calculated that our common ancestor lived 17 generations in the past at 90% probability and 22 generations in the past at 99% probability. Based on the results among the Swaims with known last common ancestors, I felt that the most likely range for the last common ancestor was probably between 15 and 18 generations.

Thus, I started my search for the last common ancestor at Generation 18 and worked my way down to Generation 15. I took information from any source available, particularly from genealogies from Dutch genealogical websites.

Results

By working down from Generation 18 to Gernation 15, I did identify an individual from Generation 15 who I believe is almost certainly the last common ancestor of the Swaims and den Hartogs. This person is Claes Willemsz Ottens Deventer (1475-1538). One of his great-great grandsons was named Matijs Barents, and Matijs Barents is almost certainly the same person as Thys Barentsen ("Thys," also spelled "Thijs," is a nickname for "Matthijs/Matijs/Matthys/Matthew." "Barents" is a shorthand form of "Barentszoon," alternative spelled "Barentsen" and meaning "son of Barent.")

This identification of Matijs Barents with Thys Barentsen is based on the identical names, the essentially identical geographic locations of residence, and the identical time in which both individuals lived. It is also based on documentary evidence indicating that Matijs Barents left his home (probably in Middelkoop) to leave the country a month before the ship De St. Jan Baptist sailed from the Netherlands to New Netherland. De St. Jan Baptist is the ship that Thys Barentsen sailed to New Netherland on, so it is unlikely to be a coincidence that both individuals of the same name living in the same place happened to leave the country at the same time. Also, this same document is one relating to the death of one of Matijs Barents' parents and to the division of the estate to the children, including to Matijs Barents. This tends to support the hypothesis that Matijs Barents and Thys Barentsen are the same person because it gives a logical reason for the timing of Thys Barentsen's emigration to New Netherland, if he was holding off emigrating while that parent was alive, perhaps because he was taking care of that parent and perhaps also to use the inheritance to fund the journey to his family's new home.

Furthermore, the very fact that I was able to locate Matijs Barents by using Y-DNA to identify the den Hartog line and then to use the den Hartog tree to search the lines branching from it, greatly increases the chances this Matijs Barents was truly Thys Barentsen. I purposely set out to identify Thys Barentsen by using the den Hartog family tree, and it is very likely that any male I found by this method would be a Y-DNA direct ancestor or collateral relative. This greatly increases the chances that Matijs Barents is truly Thys Barentsen, because Matijs Barents is likely to have been an ancestor or the cousin of an ancestor, and not some unrelated person with the same name. This was a focused search based on Y-DNA evidence that resulted in the identification of a man matching Thys Barentsen in every known respect.

There is one more reason to believe that Matijs Barents is the same person as Thys Barentsen. This is that one of Matijs Barents' paternal great-grandfather's uncles was named Jan Zweynen. This increases the likelihood that Matijs Barents is Thys Barentsen because it gives us a possible origin for the surname “Swaim” that was adopted by Thys Barentsen's descendants. The name “Zweynen” was probably pronounced “Zweyn,” whis is essentially the same as “Swain” except, perhaps, for the vowel sound in the middle. Jan Zweynen had been a wealthy and well-known man, perhaps a family legend, and so it is possible that Matijs Barents' great-grandfather, Anthonis Claessen, had adopted “Zweynen” as his surname, and that this surname had passed down unofficially to his descendants (It should be noted that Anthonis Claessen's brother, Willem, adopted the Hartog name from a different uncle (Jan Zweynen's brother Adriaen)). Alternatively, when the Swaims in New York gathered together at the dinner table to come up with a surname which the new English political bosses required of the Dutch there, they may have thought back to Jan Zweynen and chose "Swaim" in his honor (and possibly changed the terminal -n to an -m to avoid confusion with the English Swains then living in New York).  

New Swaim Family Tree

If Matijs Barents was in fact Thys Barentsen, then the last common ancestor of the Swaims and den Hartogs was Claes Willemsz Ottens Deventer (1475-1494). The Swaim line descends from Claes' son Anthonis (1516) and the den Hartog line descends from Claes' son Willem (1518).

Gen                                          Swaim/den Hartog Line

G18                                         Jan V, Heer van Arkel (1362-1428)                    

G17                                         Otto van Arkel (1400-1475) 

G16                                         Willem Ottenszn (Deventer) (1440-1494) 

G15                                         Claes Willemsz Ottens (Deventer) (1475-1538)      (Last Common Ancestor)

                         den Hartog Line                                                          Swaim Line

G14    Willem Claess den Hertoch (De Jonge)(1518-1575)                             Anthonis Claessen (1516-1568)

G13    Adriaen Willemsz van Deventer Hertoch (1560-1627)                          Mathijs Antonissen (1545-1595)

G12    Geerloff Ariensz Hartogh (den Hartog)(1589-1665)                              Barend Mathijs (1590- 1661?)

G11    Claes Geerloffsz Hartogh (den Hartog) (1624-1699)                             Matijs Barents (Thys Barentsen)(1621-1682)

There will of course be several other branches of this family tree that would be possible to identify with Y-DNA. Any male living today who comes from an unbroken male line from any male of any generation on the Swaim/den Hartog family tree will be a Y-DNA match to the Swaims and den Hartogs. Using the last common ancestor of the Swaims and den Hartogs as an example, Claes Willemsz Ottens Deventer had 4 or 5 sons other than Anthonis and Willem. Any of these sons could have established a line that might have male descendants today with "Swaim" Y-DNA. They might be using one of the surnames that others in the den Hartog tree had used (Arkel, Deventer, Ottens, Hartog, Zweynen/Zwijnen, Molenaar, Miller) or some other name. Y-DNA match Miller might be one of them, although I suspect he might have come from a couple generations above that of Claes Willemsz Ottens Deventer.

Over time other Y-DNA matches from the Netherlands will likely appear in the FTDNA database, and I predict that we will be able to locate the last common ancestor of most of them by using the same method that I was able to (probably) locate Thys Barentsen.  

There is some question as to whether the Swaim/den Hartog line is actually descended from the Lords of Arkel. There is solid circumstantial evidence that it is, and this is a question that Y-DNA may one day be able to answer. This could occur two ways. First, the remains of one of the Lords of Arkel could be tested and matched against Swaim/den Hartog DNA. Second, a known descendant of the van Arkel line could test his Y-DNA and that DNA could be matched to Swaim/den Hartog DNA. In either case a positive match would prove the relationship, and a negative match would tend to disprove it but would not definitively disprove it because there will always be some uncertainty as to whether the remains were truly of a van Arkel, or whether the descendant was truly a van Arkel.

In conclusion, Y-DNA matching identified a previously unknown branch of the Netherlands family from which the Swaims descend, and by using the family tree of that previously unknown branch the identification of Thys Barentsen within that family tree was probably established, and the known ancestry of the Swaim family was extended for at least several generations.