Genetic genealogy needs horizontal pedigree charts

Making the most of your autosomal DNA ancestry test requires understanding some simple odds and finding a good way of visualizing how genetic match connections work.

The trick is to build a picture that fits in your brain and doesn't leave you feeling overwhelmed by a morass of potentially connecting pathways. I've got one and I'll share it with you below in the hopes that it works for you too.

The most basic, probably universal, chart for "family" looks something like this:

When visualizing "ancestry", a common approach builds on the standard family chart by adding to it vertically. This is the vertical pedigree chart, which looks something like this:

You may recognize that as the structure used by Ancestry, FamilyTreeDNA and others for tree display. The tendency for genealogy and genetic testing companies to use the vertical pedigree visualization is a damn shame.

I think it is the major limit on efficiently identifying the Most Recent Common Ancestor (MRCA) between genetic matches. You'll see why in a moment.

The alternative ancestry charting method is the horizontal pedigree chart:

Notice how:

1. this is a much more space-efficient chart that is easy to display on a computer screen, (it's basically a table) and
2. each column is a nice, easy to read list of all the ancestors belonging to each ancestry level in your tree.

GEDMATCH, to its credit, uses a horizontal pedigree chart, although it's not space efficient (it does not list many generations). Why am I going on about space efficiency and the benefits of listing names per generation?

Odds, that's why.

When you receive your autosomal test results, you typically get a list of 700-1000 other testers who share at least one DNA segment with you. Looking at your list of matches and the estimated relationships between you two (provided by the testing company), you'll notice that you have a handful of relatively close matches but the vast bulk of your matches, say 995 of your 1000, will be more distant than that.

Pretend, for a moment, that all the connecting relationships for the 1000 matches were already known, the average relationship across the group would probably be something like 5th or 6th cousins. So, what do you need to know in order to identify the Most Recent Common Ancestor (MRCA) between you and the vast majority of your matches -- all these people, who are, on average, your 5th cousins?

Odds are, you need to know the fourth-great-grandparents of each tester.

If you have two full fifth cousins and you take a list of the 64 fourth-great-grandparents for each, two names on both those lists will be the same.

(simulated tree)

So, in order to effectively use your test results 99.5% of the time, you need to have lists of fourth, fifth, and sixth great-grandparents to compare. Unfortunately, none of the testing companies provide an easy way of doing this*.

None provide single view horizontal pedigrees to the fourth-great-grandparent level (or beyond). Instead, the tree structures they provide for testers to add information to are difficult to access and use.

I estimate that 90% of the completed, already researched, genealogies in the testing pool are not available by clicking on a match's name. This is a massively wasted opportunity.

As this charting method shows, in terms of odds, most matches will resolve through a shared person or couple in the list of your 64, 128, or 256 "lines" (i.e. the 4th, 5th, or 6th great grandparent level of your tree -- the farther you complete your tree, the more known lines you have and the more information you have available to figure out how you relate to someone). Most people have no trouble understanding they have a maternal and paternal side, but the exponential expansion of lines to the level of their fourth-great-grandparents is not yet part of how they see the process. Unless everyone is provided with a horizontal pedigree chart to complete to the relevant levels, efforts to identify MRCAs quickly stall.

It gets trickier to identify connecting relationship if fewer names are known (on either tree) but the same principal applies: use the testing company to estimate the level of your tree and your match's tree that should contain an overlapping couple or person (half relationships can be considered by going out one farther level than the estimate predicts). If you can't find a match, look at any missing areas on either side and consider whether the DNA and the combined information from both of you provides a clue about who the missing people could be.

This is how genetic genealogy can break through brick walls.

A seven to nine generation horizontal pedigree model provides a way of easily working with a complex situation. For full fifth cousin matches there are 32 potential pathways on your side and 32 potential pathways on your match's side (because the two sides of the final complete path between you and the match will connect at a couple).While this means that there are over one thousand potential pathways to investigate (odds that can seem overwhelming) checking two reasonably complete lists of 32 pairs of fourth-great-grandparents to find a common pair is not that hard.

So, in summary: to succeed at genetic genealogy you need to have a model of your tree and your matches' trees that allows you to easily identify the overlapping ancestors, namely shared fourth-, fifth-, and sixth-great-grandparents. Horizontal pedigree charts which run at least to the fourth-great-grandparent level allow you to do that efficiently and with an awareness of what is missing. Other methods are not as easy or effective.

***

A second reason why genetic genealogy needs horizontal pedigree charts is substantially more obvious then the one outlined above: they can provide a spatial representation of ancestry composition. Testing companies who provide ancestry composition estimates do not provide a charting tool that reveals regional contributions to the tester's DNA, but the horizontal pedigree chart can easily do this as well:

And finally, completing such a chart would give testers something to do during the long wait between sending the kit and waiting for their results to come in.

Updated: Template - this is an excel file I use (it is bigger than the above and set up to print on 11 x 17 at a copy shop). It is also expandable -- you can copy the table into a new worksheet and then each person in the last column becomes the base person of their own table, assigning them the ahnentafel number next to their name.

*Note for clarity: Apparently AncestryDNA does have a pedigree view option (I am not sure how many generations it shows on one screen). As a Canadian, I had used AncestryDNA for haplotype testing many years ago and those accounts, deleted by the company last year, did not have a pedigree tree view (or trees, if I remember correctly). Apparently those (US, Ireland) who can order the autosomal testing do have access to this.

Updated 2015-02-09 with template (see bottom). 2015-02-10 template link updated and switched to viewable sharing as someone is editing the template with their own information. Please let me know in the comments if the viewable template cannot be downloaded, thx.

Haplotype (PART 1): What's it good for?

Not much.

I kid, but haplotype results are not good for as much as most people initially assume. A common assumption seems to be that the result reflects one half of your ancestry (your maternal or paternal "side") but in fact it represents only a minuscule amount of your overall heritage.

If you made this mistake, don't worry, so has pretty much everyone who ever received results from a commercial testing company. Haplotype results are over-hyped and tend to dominate ancestry DNA reports (for reasons I won't get into here).

With this post and a couple of follow-up blogs covering investigations I am working on, I hope that I can help you navigate through the hype, bringing haplotypes to ground in the area where they are actually useful: using their logical inheritance pattern to prove/disprove theories of relationships for which no documentation can be found.

The simplest way to understand a "haplogroup" is as a grouping of Y-DNA results or mitochondrial DNA results based on shared variants in the 59 million bases in a male's Y chromosome or or 16.6 thousand bases in anyone's mitochondrial DNA. (This is how the term haplogroup is used in genetic genealogy, biologists use it for all sorts of stuff).

Every individual tested who shares the exact same variants at key locations on the relevant chromosome is assigned the same haplotype. They all inherited these variants from ancestral lines that lead back to the same person a very, very long time ago. Likely tens of thousands of years ago, given the resolution of most basic tests (if you've used a high resolution STR marker test you probably already know this stuff so I don't feel bad about making a slight oversimplification about timelines).

Everyone in a group got their variants from the same person many thousands of years ago, and still has the same sequence of variants, because of two simple facts: Y-DNA gets passed down from father to son without recombining, and mitochondrial DNA is the non-nuclear DNA inherent in the egg cell itself (the sperm's mitochondrial DNA does not survive fertilization) so it also passes intact, but from mothers to all of their children. You, your mom, and her mom's mom's mom, etc. in a straight line of maternal relationships, all have the same mtDNA haplotype. There is a small mutation rate, but don't worry about it until you've become more expert in using haplotypes.

So, how does that type define you?

It really doesn't reflect much about your complete genetic make-up.

Categorizing 16.6 thousand base pairs out of a total of 3 billion is categorizing a measly 0.0005% of who you are, genetically. Women don't even have a Y chromosome and for men it is only about 2% of their total genetic make-up. However, as insignificant as these percentages are, these are the only groupings of DNA that can be made to reflect ancient ancestry and follow a specific logical inheritance pattern, because all your other DNA emerged from mixing events every single time one of your ancestors was conceived. So, the fact that these pieces of DNA do not change and are associated with specific people in every ancestry chart is pretty cool and can be a powerful tool in certain investigations.

So, your haplotype does not really define much about your overall genetic identity, does it tell you much about your relationships with genetic matches on autosomal tests?

I'll answer that in PART 2...

You are a third cousin of Richard III

If you are English of predominantly English ancestry.

If you are from the broader UK, Commonwealth, or a former colony with any antecedents from the UK, the odds are still good that you are also at least a third cousin of Richard III. The populations of several other European countries are also home to many, many cousins of Richard III, particularly Spain and Portugal, wherein lay the marital destinies of some of his female third cousins. If you are in the west but not of western ancestry, over time, your relatives or descendants will very likely marry a third cousin of Richard III.

How is this possible?

Andrew Millard, a genealogist in Durham, UK, has attempted to calculate "the probability that a present-day English person descends from Edward III." Millard's conclusion is that the probability is well over 99%. As Edward III is the 2nd great-grandfather of Richard III, the odds are you have an ancestral line that runs straight through one of Edward's other great-great-grandchildren, all of whom were third cousins to Richard III.

However, the question remains how many generations removed you are from that point. Benedict Cumberbatch, for instance, is his third cousin, 16 times removed.

You may also have a closer than third cousin relationship to Richard III, as he had nieces and nephews, first and second cousins, with lines surviving to this day. And, he has many lines of cousins that descend from his great-great grandparents other than Edward III (in fact, his maternal line 2nd great grandmother, the mother of Katherine de Roet Swynford, is not even known, so anything is possible).

In fairness, the University of Leicester is claiming only one to 17 million people have connections to Richard III. However, they are not indicating how their probability calculations vary from Millard's (and they may not be familiar with his work). In the days leading up to Richard III's interment, and as his burial site in Leicester becomes a tourist attraction, considering these connections can make history very tangible, universal, and personal.

Richard III's nieces and nephews (who had children)

Richard is, infamously, a suspect in the deaths of two of his nephews. However, several of his other nieces and nephews had children with descendant lines surviving to today.  Eight of his nieces and nephews, many times removed, were reportedly involved in the legal dispute over whether he would be interred in York or Leicester. His living nieces and nephews descend from the legitimate and illegitimate children of his siblings who are known to have had offspring:

• Anne St. Leger (14 January 1476 – 21 April 1526), who married George Manners, 11th Baron de Ros
• Michael Ibsen is in this line in a completely female descent (which means he carries the mtDNA of Richard), but there are also may who do not follow a single-sex descent line
• Elizabeth of York, queen consort to Henry VII of England (11 February 1466 – 11 February 1503)
• Queen Elizabeth is niece of Richard III, 16 times removed, through this line (Margaret Tudor>Margaret Douglas>Henry Stuart, Lord Darnley>James VI>Elizabeth Stuart, Queen of Bohemia>Sophia, Princess Palatine>George I>George II>Frederick, Prince of Wales>George III>Prince Edward, Duke of Kent and Strathearn>Queen Victoria>Edward VII>George V>George VI>Elizabeth II)
• Cecily of York (20 March 1469 – 24 August 1507), married first John Welles, 1st Viscount Welles and second Thomas Kyme or Keme
• Anne of York (2 November 1475 – 23 November 1511), married Thomas Howard (later 3rd Duke of Norfolk)
• Catherine of York (14 August 1479 – 15 November 1527), married William Courtenay, 1st Earl of Devon
• Elizabeth Plantagenet (born circa 1464), married Thomas Lumley, Esquire, of Beautrove, Durham
• Arthur Plantagenet, 1st Viscount Lisle (1460s/1470s – 3 March 1542), married Elizabeth Grey
• Mary Plantagenet, married Henry Harman of Ellam
• A daughter said to have been the first wife of John Tuchet, 6th Baron Audley
• Margaret Pole, 8th Countess of Salisbury (14 August 1473 – 27 May 1541), married Sir Richard Pole

Anyone who directly descends from someone on the above list is a niece or nephew of Richard III (removed as many generations as they are separated from the person above).

Richard III's first cousins (survived to adulthood, not known to be childless)

Anyone directly descended from someone on the list below is a first cousin of Richard III (removed as many generations as they are separated from the person below).

Father's side

• William Bourchier, Viscount Bourchier (d. 1480), married Anne Woodville
• Sir Henry Bourchier (d. 1462), married Elizabeth Scales, 8th Baroness Scales.
• Humphrey Bourchier, 1st Baron Cromwell (d. 14 April 1471), slain at the Battle of Barnet.
• John Bourchier, 6th Baron Ferrers of Groby (d.1495), married firstly Elizabeth Ferrers, and secondly Elizabeth Chichelle
• Sir Thomas Bourchier (b. prior to 1448 d. 1492), married Isabella Barre
• Edward Bourchier (d. 30 December 1460), slain at the Battle of Wakefield (offspring?)
• see also Sir Thomas Grey below

Mother's side

• Ralph Neville, 2nd Earl of Westmorland, married Elizabeth Percy, married Margaret Cobham
• John Neville, Baron Neville, married Anne Holland
• Sir Thomas Neville, married Elizabeth Beaumont
• Margaret Neville, married Sir William Lucy
• Havisia Neville, married Sir William Bradford Heslerton
• Joan Neville, married Walter Hart Griffith
• John Neville, married Lucy Somerset, married Margaret Plumpton, married Elizabeth Newmarch
• Sir Thomas Grey (1404 – d. before 1426), married Isabel of Cambridge (Richard III's paternal aunt) and some sources indicate they had a son before the marriage was annulled - line most likely died out at this point
• Sir Ralph Grey (d. 17 March 1442), married Elizabeth FitzHugh
• Eleanor Grey, married Sir John Arundel
• Joan Grey, married Sir John Salvin
• Elizabeth Grey, married firstly, Sir William Whitchester, and secondly, Sir Roger Widdrington
• Margaret Grey, married Gerard Widdrington
• Sir Gilbert Lancaster
• Sir Thomas Dacre (d. before 5 January 1458), married Elizabeth Bowet
• Humphrey Dacre, 1st Baron Dacre of Gilsland (d. 30 May 1485), married Mabel Parr
• Joan Dacre, married Thomas Clifford, 8th Baron de Clifford
• Margaret Dacre, married John le Scrope
• Henry Scrope, Baron Scrope of Bolton, married Elizabeth Scrope
• Isabella Scrope, married Richard Plumpton 
• Margaret Scrope, married Thomas Grey, Baron Richemond
• Alexander Cressener of Alphamstone (b. c. 1422 - d. 18 Jun 1498), married Alicia Radcliffe
• Cecily Neville (1424–1450), married Henry de Beauchamp, 1st Duke of Warwick, line subsequently died out
• Richard Neville, 16th Earl of Warwick (1428–1471), married Lady Anne Beauchamp 
• Alice Neville (c.1430–1503), married Henry FitzHugh, 5th Baron FitzHugh 
• John Neville, 1st Marquess of Montagu (?1431–1471), married Isabel Ingaldesthorpe 
• Joan Neville (1434–1462), married William FitzAlan, 16th Earl of Arundel
• Katherine Neville (1442–1503), married first William Bonville, 6th Baron Harington, and second William Hastings, 1st Baron Hastings
• Eleanor Neville (1447–1482), married Thomas Stanley, 1st Earl of Derby
• Lady Alice Neville, married Sir John Conyers
• Lady Elizabeth Neville, married Sir Richard Strangeways
• Lady Joan Neville, married Sir Edward Bedhowing
• Sir Henry Neville (d. 26 July 1469), married Joan Bourchier
• Thomas Neville, of Shenstone, Staffordshire ?
• Jane Neville, some sources report she married Oliver Dudley
• Richard Nevill (1439 – bef. 1476) ?
• Sir George Nevill (c.1440–1492), married Margaret Fenne (ancestors to George Washington), married Elizabeth 
• Alice Nevill, married Sir Thomas Grey
• Catherine Nevill (b.c. 1444), married John Iwardby
• Catherine Nevill (b. c. 1452/bef. 1473) married Robert Tanfield (b. 1461) (ancestor of Thomas Jefferson)
• Margaret Nevill (b.bef. 1476-1506), married John Brooke, 7th Baron Cobham
• John de Mowbray, 3rd Duke of Norfolk (1415–1461), married Eleanor Bourchier
• Joan Strangeways, married Sir William Willoughby (they were ancestors of Herbert Hoover, among many others)
• Katherine Strangeways, married Henry Grey, 4th (7th) Baron Grey of Codnor
• Henry Percy, 3rd Earl of Northumberland (25 July 1421 - 29 March 1461, Battle of Towton), married Eleanor Poynings
• Thomas Percy, 1st Baron Egremont (29 November 1422, Leconfield, Yorkshire - 10 July 1460, Battle of Northampton, England), married Eleanor Percy
• Lady Katherine Percy (28 May 1423 - d. aft 1475), married Edmund Grey, 1st Earl of Kent
• Sir Ralph Percy (1425 - 25 April 1464, Battle of Hedgeley Moor), married Eleanor Acton, married Jane Teye
• Sir Richard Percy (1426/7–29 March 1461, Battle of Towton), married Catherine Percy, of Thornton-Bridge
• Humphrey Stafford, Earl of Stafford (d. 1458), married Margaret Beaufort, Countess of Stafford
• Catherine Stafford (1437 – 26 December 1476), married John Talbot, 3rd Earl of Shrewsbury
• John Stafford, 1st Earl of Wiltshire (d. 8 May 1473), married Constance Green
• Joan Stafford (1442–1484), married first William Beaumont and secondly William Knyvett
• Anne Stafford (1446–1472), married first Aubrey de Vere, son of John de Vere, 12th Earl of Oxford, married secondly Thomas Cobham, 5th Baron Cobham
• Margaret Stafford, married Robert Dunham

Richard III's second cousins 

coming soon

Richard III's third cousins 

coming soon

Were Richard III's parents second cousins as expected?

Isabella of Castille:
 Unfaithful wife of Edmund,
Duke of York?

As I wrote previously, the investigation of Richard III's skeleton revealed that he does not share the same Y-DNA as his putative paternal-line relative Henry Somerset, 5th Duke of Beaufort and there are 18 possible birth events where non-paternity may have occurred.

There are four possible breaks between Edward III and Richard's own birth. One of the more probable false paternity events would be the birth of his grandfather, Richard of Conisburgh. Another is the birth of John of Gaunt. Provided the researchers were able to extract sufficient autosomal DNA, there is a simple, free, test which may reveal that there is a false paternity within these five steps of the broken line (John of Gaunt-Edward III-Edmund of York-Richard of Conisburgh-Richard Plantagenet-Richard III).

Gedmatch.com has a tool which can take autosomal DNA testing results and compare one side of a chromosome pair against the other, looking for similarities in regions which are expected to vary. It can then estimate which percentage of the DNA on each side is likely to have come from a common ancestor and how many generations back (basically based on amounts shared). Everyone gets one side of each chromosome pair from their father and one from their mother and if the parents are not related, there will be the expected variety and little similarity. The test evaluates how related an individual's parents are without having to test anyone but the individual.

According to the genealogy, Richard's parents are supposed to be, at their closest relationship, 2nd cousins (generations to most recent common ancestor would be about 4). His maternal grandmother's father should be the brother of his paternal grandfather's father. These brothers are John of Gaunt and Edmund of York and both paternity events are key interconnected steps on the broken line.

Additionally, Richard's father is supposed to be the 2nd cousin twice removed of his mother as his father's mother, Ann Mortimer, was also descended from Edward III, as the granddaughter of one of his granddaughters. Finally, his parents should have an additional more distant cousinship from common ancestry that is not related to Edward III.

Therefore, five steps in the paternity line happen to be uniquely tied to this supposed 2nd cousin relationship. Running Richard III's autosomal DNA results through the parental consanguinity calculator should indicate his parents have a common ancestor about 4 generations back. If the result is that the ancestor is farther back than 4 generations (or that his parents are unrelated), there is a break in the paternity line in the five steps between John of Gaunt and Richard III.

The key question is, have the researchers recovered enough autosomal DNA?

Infidelity possibilities in the line between Richard III and Henry Somerset

As demonstrated in Nature Communications, a multidisciplinary investigation of Richard III's skeleton revealed at least one non-paternity event in the 19 generations separating Richard III from his putative paternal-line relative Henry Somerset, 5th Duke of Beaufort. Looking at the events surrounding the conception and birth of all 19 individuals may help illustrate where the breakage (or breakages) most likely occurred.

As Ed West pointed out, "in primates, including humans, high-status males are rarely cuckolded; on top of everything else a king could have his wife beheaded if caught, something your average man couldn't get away with." Therefore, relative status of the father within each relationship needs to be considered, along with whether the child was an heir presumptive at time of conception. Births of sons to reigning male monarchs or males first in line to the throne are underlined below. These would represent both treasonous infidelities and counter the known improbability for a high status (in such a case, arguably the highest status) male to be cuckolded, and therefore are much less likely than other scenarios. Other birth scenarios and event characteristics which may increase the probability for infidelity are in red.

Four potential breaks: The births from Edward III to Richard III

• 5 June 1341 birth at  Kings Langley Palace in Hertfordshire of Edmund, Duke of York (died 1402): He was the fifth son and seventh child of the marriage of a reigning monarch, Edward III to Philippa of Hainault. He was conceived in 1340 when his mother was 26 years old and 12 years after his mother was crowned queen. All of her children were born one to three years apart over a 25 year period 1330-1355, when she was aged 15 to 41. They had five children after Edmund. She was known for travelling with her husband throughout their marriage. No time apart between the two in 1340 has been identified by preliminary Internet research.

• Approximately 20 July 1375 birth at Conisbrough Castle, Yorkshire, of Richard, Earl of Cambridge (died 1415). He was conceived as the second son and third child of the marriage of Edmund and Isabella of Castille, the youngest daughter of Peter the Cruel, King of Castille. At the time he was conceived, Edmund was Earl of Cambridge, the fifth son of the King and no closer than sixth in line to the throne (making Richard, if born male, 8th in line). Edmund was not well regarded, described as a man without the abilities suited to his station, while Isabella was the daughter of a reigning monarch known for despotism. Richard was his mother's third and last child, born when she was about 20, although she lived for another 17 years and Edmund outlived her. She had married Edmund when she was 17 and had a firstborn son, a daughter, and Richard within three years. In a 1988 book, modern scholar T.B. Pugh concluded "they were an ill-matched pair."  There are significant problems with the paternity of Richard, Earl of Cambridge that greatly increase the probability this is a non-paternity event:
• The Yorkist claim to the throne made by his grandsons ran through the line of his wife, Ann Mortimer, and not through him.
•  Wikipedia notes: "As a result of her indiscretions, including an affair with King Richard II's half-brother, John Holland, 1st Duke of Exeter (d.1400), whom Pugh terms 'violent and lawless', Isabella left behind a tarnished reputation, her loose morals being noted by the chronicler Thomas Walsingham. According to Pugh, the possibility that Holland was the father of Isabella's favourite son, Richard of Conisburgh, 3rd Earl of Cambridge, 'cannot be ignored'."
• "according to Harriss, since he received no lands from his father, Edmund ... Duke of York, and was not mentioned in either his father's or his brother's wills, he may have been the child of an illicit liaison between his mother and John Holland, 1st Duke of Exeter."
• The Y-DNA line of John Holland goes back to Sir Robert de Holland of Upholland, Lancashire, born about 1250. Haplogroup G could be expected to have a 1-2% prevalence in Lancashire at that time, with an unknown but possible presence for subclade G2. John Holland's male line is not known to have persisted at this time.
• 21 September 1411 birth of Richard, Duke of York. He was the third child and second son, but probably only surviving son of the marriage of Richard, Earl of Cambridge and Ann Mortimer. Ann died shortly after he was born, aged about 20. Ann was for much of her life the daughter of the heir presumptive to the throne, and briefly the sister of the heir presumptive until Richard II was deposed by the Lancastrians.
• 2 October 1452 birth of Richard III at Fotheringhay Castle, the eighth son (probably fifth or sixth surviving) and twelfth child of Richard Plantagenet, 3rd Duke of York and Cecily Neville. When Richard was conceived in 1451, his father, Richard Plantagenet was the wealthiest and most powerful noble in England, other than the king, and had the leading Yorkist claim to the throne. Cecily Neville was noted for her pride, temper, and piety. Her children were all born 1-3 years apart over a 17 year period when she was aged 22 to 40. No time apart between the two early in 1452 is noted. The couple had one other child after Richard.

Fourteen potential breaks: The births from Edward III to Henry Somerset

• 6 March 1340 birth in Ghent of John of Gaunt. He was the fourth son and sixth child of the marriage of a reigning monarch, Edward III to Philippa of Hainault. He was conceived in 1339 when his mother was 25 years old and 11 years after his mother was crowned queen. All of her children were born one to three years apart over a 25 year period 1330-1355, when she was aged 15 to 41. They had six children after John. She was known for travelling with her husband throughout their marriage. Rumours circulated that he was the son of a Ghent butcher but only later in his life after he became unpopular and were based on a spurious conclusion that Edward III’s absence from his birth was significant (investigating the timing of these rumours, given the 1374 conception and 1375 birth of Richard of Conisburgh which seems to have the highest probability of being a non-paternity event, now has greater priority given the DNA results).
• 1373 birth of John Beaufort. He was the first of four illegitimate children of the relationship of John of Gaunt, Duke of Lancaster and son of the king at the time John was conceived, and Katherine de Roet Swynford. While not married, the power differential between the couple is more in favor of actual paternity than not. John and Katherine had three sons and a daughter (1373, 1375, 1377, and 1379). Katherine had previously married Hugh Swynford and had children with him (about 1369 and 1367, and possibly two more for which details are unavailable) before he died in 1371/2. John’s second wife, Constance of Castille (sister of Isabella who married Edmund, Duke of York and may be responsible for the non-paternity event on the other s) died in 1394 and John married Katherine in 1396. The pope legitimized their children shortly after, as did Richard II by 1399.
• 1406 birth of Edmund Beaufort. He was the third son and fifth child of six children of the marriage of John Beaufort, legitimated grandson of a sovereign and Earl of Somerset at the time of Edmund’s conception and Margaret Holland. Margaret appears to have had the six children between 1401 and 1409 when she would have been aged 16-24. Edmund died in 1410. Margaret then married Edmund’s nephew, Thomas of Lancaster, 1^st Duke of Clarence, but the couple had no children. She died thirty years later in 1439.
• 26 January 1436 birth of Henry Beaufort. He was the third child and eldest son of Edmund Beaufort, heir to the Duke of Somerset at the time Henry was conceived, and Eleanor Beauchamp. While Edmund “was the head of one of the greatest families in England, his inheritance was worth only 300 pounds.” Edmund and Eleanor were probably married about 1425 and had two daughters before Henry and then four more sons and three more daughters. Eleanor seems to have had her last child about 1455 when she would have been 47 and which was the year Edmund died. There may or may not have been a gap between the children in the 1440s as evidence providing detailed birth dates is scant. Eleanor lived until 1467.
• Circa 1460 birth of Charles Somerset. He is the only known son of the relationship of Henry Beaufort, Duke of Somerset at the time of his conception, and his mistress Joan Hill. Born illegitimate, he was legitimized later in life by his father. Little is known of Joan Hill, but the relative status difference in the couple was in favor of actual paternity rather than not.
• Circa 1496 birth of Henry Somerset [full disclosure: my 13th great grandfather, genealogically]. He was the only son of two children of the marriage of Charles Somerset, a Knight of the Garter (and illegitimate son of Henry Beaufort, 3^rd Duke of Somerset) at the time Henry was conceived, and Elizabeth Herbert, 3^rd Baroness Herbert. Charles and Elizabeth married 2 June 1492 and only two children are known. Charles was created Lord Herbert in right of his wife. Elizabeth is known to have died before 1513 but in which year is not clear.
• Circa 1526/7 birth of William Somerset. He was the eldest son of Henry Somerset, Earl of Worcester at the time (or shortly after) William was conceived, and Elizabeth Browne. William and Elizabeth were married before 1526/7 and are known to have had three more sons and four daughters after William. Elizabeth was lady-in-waiting to Anne Boleyn and her main accuser. Updated: Her accusations were apparently a reaction to her own adultery coming to light in 1536.
• Approximately 1550 birth of Edward Somerset. He was the only son of three children born to William Somerset, Earl of Worcester at the time (or shortly after) Edward was conceived, and Christian North. William and Christian are known to have had two daughters in addition to Edward, but birth dates and additional details are scant.
• 1577 birth of Henry Somerset. He was the eldest surviving son of Edward Somerset, heir to the Earl of Worcester at the time of his conception, and Elizabeth Hastings. Edward and Elizabeth married in December 1571 and are known to have had fifteen children. Edward was an important advisor to King James I and served as Lord Privy Seal.
• 9 March 1602 or 1603 birth of Edward Somerset. He was the firstborn of nine sons and four daughters of the marriage of Henry Somerset, son and heir to the Earl of Worcester at the time of his conception, and Anne Russell. Henry was considered an “outstandingly wealthy peer.” Henry and Ann married 16 June 1600 and had thirteen children after Edward.
• 1629 birth at Raglan Castle of Henry Somerset. He was the firstborn and only son of Edward Somerset, Lord Herbert of Raglan at the time of his conception, and Elizabeth Dormer. Edward and Elizabeth married in 1628, shortly after Edward graduated from Cambridge University with a Master of Arts degree and when he was still one of the richest lords in England. Elizabeth had a daughter about 1631 and another before 1635 when she died.
• 25 December 1660 birth of Charles Somerset. He was the second but eldest surviving son of Henry Somerset, Lord Herbert at the time of his conception, and Mary Capell. Henry and Mary had married, using the “republican” form of marriage before a justice of the peace (Wikipedia) in 1657 and Henry made himself acceptable to Cromwell and survived the interregnum. However, he was involved in the Royalist plot of July 1659 and was committed to the Tower of London. A letter he wrote to his wife from the Tower in August of 1659 survives. Henry was released 1 November 1659 and Charles was conceived about five months later. Mary had previously been married to Henry Seymour and had two children by him before he died in the Tower in 1654. As outlined above, she married again in 1657, had a son before 1660 who died as an infant, had Charles in 1660 when she was aged 30, and then likely had four daughters and one more son (1663, 1664, a gap until 1670, 1671, and 1673).
• 2 April 1684 birth at Monmouth Castle of Henry Somerset. He was the eldest child and only son of the marriage of Charles Somerset, the Marquess of Worcester and heir presumptive to the dukedom at the time of his conception, and Rebecca Child. Rebecca married Henry in 1682, had Henry in 1684 and a daughter eight years later in 1690. It is not known if other pregnancies occurred or children who did not survive were born in the interval. The couple are not known to have had further pregnancies or children between 1690 and Charles’ untimely death in a coach accident in 1698, aged 37. The dukedom skipped to Henry when Charles’ father died in 1700.
• 12 September 1709 birth of Charles Noel Somerset. He was the second son of Henry Somerset, 2^nd Duke of Beaufort at the time of his conception, and Henry’s second wife, Rachel Noel. Rachel married Henry in 1706 and bore him a son Henry in 1707 and then Charles in 1709, shortly after which she died. Henry himself died in 1714, at the young age of 30, after marrying a third time (no issue) in late 1711.
• 16 October 1744 birth of Henry Somerset. He was the third child and firstborn son (ultimately only son) of Charles Noel Somerset (who was the heir presumptive his childless brother’s dukedom at the time of his conception in 1744) and Elizabeth Berkeley. Elizabeth was 31 years old when he was born, having married Charles Noel Somerset four years prior and born two daughters earlier. The couple would go on to have three more daughters, one in 1746, one in 1748, and one after a gap of 8 years in 1756 (the last arrived when Elizabeth was 43 years old).  

Appendix: Understanding where Edward III's Y-DNA came from and haplotype probabilities

According to Wikipedia, Edward the III's Y-DNA line traces to Fulcois, the Count of Perche, a French noble living in the 900-1000s who was probably of the family of viscounts from Châteaudun in northern France.

Fulcois (if there were no non-paternity events along the descent to Edward III), was Edward's 9th great grandparent via:

1. Hugues du Perche, born northern France (probably Châteaudun), the youngest son of Fulcois (the count of Perche at the time of his conception)
2. Geoffrey II, born northern France, probably firstborn son (of the count of Perche at the time of his conception), became the Count of Gâtinais and married a Duchess of Burgundy
3. Fulk IV, born in northern France, the younger son of the above (who was Count of Gâtinais at the time of his conception).
4. Fulk V of Anjou, born between 1089 and 1092 at Angers, a city in western France, as the second son, and the only known child of his parents, Fulk IV (Count of Anjou at the time of his conception) and Bertrade de Montfort (Bertrade was Fulk's fifth wife). In 1092, aged about 22, Bertrade left Fulk IV and bigamously married Philip I, King of France.
5. Geoffrey V, aka Geoffrey Plantagenet, born 24 August 1113, presumably northwestern France,  the firstborn son and probably third child of Fulk V (Count of Anjou at the time of his conception)
6. Henry II, born 5 March 1133 at Le Mans, France, the eldest child of the above and Empress Matilda
7. John, King of England, born in Anjou or Aquitaine, France, 24 December 1166, the sixth son and ninth child of reigning monarch King Henry II and Eleanor of Aquitaine
8. Henry III, born at Winchester Castle, Hampshire, England, 1 October 1207, the firstborn son of the king 
9. Edward I, born at the Palace of Westminster, London, England, the night of 17-18 June 1239, firstborn son of the king
10. Edward II, born 25 April 1284 in Caernarfon Castle in North Wales, the fourth son of the king (two older brothers died before his birth and a third died four months after he was born, so a potential heir presumptive at time of conception).
11. Edward III, born 13 November 1312 at Windsor Castle, Windsor, England, firstborn son of the king

Two Y-DNA haplotypes were identified in the Richard III investigation as the possible Plantagenet type.  The two types are are G2 (P287) for the Richard III skeleton, and R1b1b (U152) for Henry Somerset, 5th Duke of Beaufort (as reliably triangulated from descendants).

However, there may be multiple non-paternity events, in which case it is possible neither is the true Plantagenet type and/or Edward III's type.

Both haplotypes are found in modern populations in Britain and France, but R1b1b (U152) is substantially more common than G2 (P287):

• According to Eupedia, R1b1b (U152):
• has a prevalence of 10-15% in north western France and reaches 15-20% in northern France. A peak of 20-30% is found on the far eastern border of France and in a pocket centered on Poitou, south of Anjou.
• has a prevalence of 10-15% in pockets of south eastern England fading as it moves westward to a prevalence of less than 1% in Wales.
• While Richard's type is G2, according to Eupedia, most Europeans who are G belong to subclade G2a:
• and G haplogroup overall is found at a small prevalence of 1-2% in both northern France and England, outside of Wales where the prevalence increases slightly to 3-5% and an area near Calais that can show a prevalence as high as 6-8%. The prevalence of subclade G2 is significantly less than that for G as a whole and it is considered a very rare type.

Therefore, assuming the modern maps do not fundamentally misrepresent a basic availability of both groups in France and England in the 900s, either haplogroup makes sense as a Plantagenet type, based on the known origin of the line at Châteaudun, or as a type introduced to the line by a European or Middle Eastern interloper.

Diagram of how 4th cousin matches work in autosomal DNA testing

Simulated relationship between two DNA testers who show on each other's match lists as 4th cousins. The ancestry of one tester is represented on the left (starting with her parent's generation) and a second person who matches with 1 segment, 14 cM or 0.19% is represented on the right (also starting at parents generation). Note the complex inheritance of haplotypes, which are not shared between the matches.