# Prince William marrying a distant cousin **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [March 31, 2011, 1:10pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621 "2011-03-31T13:10:02Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [March 31, 2011, 9:23pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/21 "2011-03-31T21:23:45Z")
> [@PunditLisa](#): > > Back in Cleopatra’s day, they married their siblings. > > YUCK! To be fair, a pharoah only married one (half-)sibling. It wasn’t _polygamous_ incest. ---
**Author:** ![Sampiro](https://avatars.discourse-cdn.com/v4/letter/s/2acd7d/32.png) [@Sampiro](https://boards.straightdope.com/u/Sampiro)\ **Post date:** [March 31, 2011, 10:22pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/22 "2011-03-31T22:22:41Z")
> [@Dr.Drake](#): > > To be fair, a pharoah only married one (half-)sibling. It wasn’t _polygamous_ incest. Sometimes it was. Ramses the Great was married to at least one of his sisters and at least three of his daughters. ---
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [March 31, 2011, 11:17pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/23 "2011-03-31T23:17:07Z")
> [@Sampiro](#): > > Sometimes it was. Ramses the Great was married to at least one of his sisters and at least three of his daughters. Huh. The things I learn here! Thanks for this, I think… ---
**Author:** ![Shayna](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/shayna/32/17976_2.png) [@Shayna](https://boards.straightdope.com/u/Shayna)\ **Post date:** [March 31, 2011, 11:24pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/24 "2011-03-31T23:24:11Z")
> [@Bijou\_Drains](#): > > His future wife is a 14th cousin once removed. **She is also related to George Washington** and Guy Ritchie > > [http://www.cnn.com/video/#/video/world/2011/03/30/boulden.rw.kate.ancestry.cnn?hpt=C2](http://www.cnn.com/video/#/video/world/2011/03/30/boulden.rw.kate.ancestry.cnn?hpt=C2) Well then she has something in common with President Obama, who is a [9th cousin 6 times removed from George Washington](http://www.geni.com/path/George+Washington+1st+President+of+the+USA+is+related+to+Barack+H+Obama+44th+President+of+the+USA?from=6000000008211776777&to=6000000010349180549)! ---
**Author:** ![TruCelt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/trucelt/32/523_2.png) [@TruCelt](https://boards.straightdope.com/u/TruCelt)\ **Post date:** [March 31, 2011, 11:45pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/25 "2011-03-31T23:45:37Z")
> [@Sampiro](#): > > Sometimes it was. Ramses the Great was married to at least one of his sisters and at least three of his daughters. eWWWWWWWW! Pass the brain leach, please!\* \*This typo is worth leaving, I think. 😉 ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [April 1, 2011, 12:32am UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/26 "2011-04-01T00:32:46Z")
Weird I saw this tidbit this evening on E! News and they pushed the story with Ellen DeGeneres as her 14th cousin, and also mentioned George Washington. No mention of William being a cousin. Ah…“news”… ---
**Author:** ![Double\_Foolscap](https://avatars.discourse-cdn.com/v4/letter/d/85e7bf/32.png) [@Double\_Foolscap](https://boards.straightdope.com/u/Double_Foolscap)\ **Post date:** [April 1, 2011, 11:30am UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/27 "2011-04-01T11:30:05Z")
> [@Shayna](#): > > Well then she has something in common with President Obama, who is a [9th cousin 6 times removed from George Washington](http://www.geni.com/path/George+Washington+1st+President+of+the+USA+is+related+to+Barack+H+Obama+44th+President+of+the+USA?from=6000000008211776777&to=6000000010349180549)! No way - George Washington was a Kenyan? 😃 ---
**Author:** ![Dangerosa](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Dangerosa](https://boards.straightdope.com/u/Dangerosa)\ **Post date:** [April 1, 2011, 12:39pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/28 "2011-04-01T12:39:40Z")
> [@Double\_Foolscap](#): > > No way - George Washington was a Kenyan? > > 😃 And he wasn’t a true American since he wasn’t born on American soil. How much they have in common! ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [April 1, 2011, 1:06pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/29 "2011-04-01T13:06:49Z")
> [@Double\_Foolscap](#): > > I’m outraged. He should be marrying somebody no less related than a third cousin. What’s modern royalty coming to these days? I agree, what if this rampant genetic mixing actually results in children who have more skills other than waving from cars? They may no longer be content to just sitting around in palaces waiting to bleed to death and actually try and interfere to the real world. \ ---
**Author:** ![SecondJudith](https://avatars.discourse-cdn.com/v4/letter/s/b5ac83/32.png) [@SecondJudith](https://boards.straightdope.com/u/SecondJudith)\ **Post date:** [April 1, 2011, 1:17pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/30 "2011-04-01T13:17:24Z")
> [@Sampiro](#): > > As seen in that play about you, _Less than 14 Degrees of Separation_. Ah yes; the British original was _Fewer than 14 Degrees of Separation_, IIRC. 😃 ---
**Author:** ![Colophon](https://avatars.discourse-cdn.com/v4/letter/c/f05b48/32.png) [@Colophon](https://boards.straightdope.com/u/Colophon)\ **Post date:** [April 1, 2011, 3:51pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/31 "2011-04-01T15:51:49Z")
> [@Shayna](#): > > Well then she has something in common with President Obama, who is a [9th cousin 6 times removed from George Washington](http://www.geni.com/path/George+Washington+1st+President+of+the+USA+is+related+to+Barack+H+Obama+44th+President+of+the+USA?from=6000000008211776777&to=6000000010349180549)! Obama’s mother was called Stanley? Not only was he born in Kenya, he was born to a _man_, baby! 😛 ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [April 1, 2011, 6:11pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/32 "2011-04-01T18:11:21Z")
> [@Dr.Drake](#): > > Their common ancestor is Edward I. I would be interested in knowing what percentage of Englishmen are NOT descended from Edward I. He lived in the 13th century and had at least 7 children who survived to produce heirs. I bet there’s a mathematical model that could work with those numbers; anyone know how to do it? If you’re looking for a very crude estimate giving the portion (p) of Englishmen living in year Y who are not descended from Edward I, you can try a [logistic function](http://en.wikipedia.org/wiki/Logistic_function) like: p = A e[sup](1300 - Y)/G[/sup] / (1 + A esup/G[/sup] ) where A = 2,000,000 is the number of males when Edward starting having children in 1300 A.D., and G = 38 is a very crude estimate of years needed for growth of x2.72. Plugging into this formula gives 99.9%, 98%, 79%, 22%, 2% for years 1585, 1700, 1800, 1900, 2000. But the flaws in this crude formula would make a very long list! It ignores emigration/immigration, assumes random mating, ignores that Edward had several children, and G was a wild guess, just for starters. I vaguely recall once reading “almost every Englishman is descended from King John” which might be a plausible stab. ---
**Author:** ![Katriona](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/katriona/32/113_2.png) [@Katriona](https://boards.straightdope.com/u/Katriona)\ **Post date:** [April 1, 2011, 7:40pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/33 "2011-04-01T19:40:36Z")
> [@Dangerosa](#): > > And he wasn’t a true American since he wasn’t born on American soil. How much they have in common! Probably didn’t have a long-form birth certificate, either. Hmmph. Poser! ---
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [April 1, 2011, 8:19pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/34 "2011-04-01T20:19:03Z")
> [@septimus](#): > > If you’re looking for a very crude estimate giving the portion (p) of Englishmen living in year Y who are not descended from Edward I, you can try a [logistic function](http://en.wikipedia.org/wiki/Logistic_function) like: > > p = A e[sup](1300 - Y)/G[/sup] / (1 + A esup/G[/sup] ) > > where A = 2,000,000 is the number of males when Edward starting having children in 1300 A.D., and G = 38 is a very crude estimate of years needed for growth of x2.72. > > Plugging into this formula gives 99.9%, 98%, 79%, 22%, 2% for years 1585, 1700, 1800, 1900, 2000. > > But the flaws in this crude formula would make a very long list! It ignores emigration/immigration, assumes random mating, ignores that Edward had several children, and G was a wild guess, just for starters. I vaguely recall once reading “almost every Englishman is descended from King John” which might be a plausible stab. This is really interesting, thank you. So in my case, slightly under 3% of my ancestors are English, and by 1700 they had all left England and soon started marrying non-English. So that gives me (1-.98)\*.0275 = only a miniscule likelihood of being descended from Edward I. Even so I know that Obama and I share an ethnically English ancestor from mid-18th-century Virginia. I ❤ pedigree collapse. ---
**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\ **Post date:** [April 1, 2011, 9:25pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/35 "2011-04-01T21:25:10Z")
> [@Dr.Drake](#): > > So in my case, slightly under 3% of my ancestors are English, and by 1700 they had all left England and soon started marrying non-English. So that gives me (1-.98)\*.0275 = only a miniscule likelihood of being descended from Edward I. Even so I know that Obama and I share an ethnically English ancestor from mid-18th-century Virginia. I ❤ pedigree collapse. Two caveats: (1) My crude formula was intended more as an example of the indicated math, rather than an authoritative formula for this specific question. (2) Your calculation seems to assume a zero chance that a non-Englishman (or non-Brit?) descends from Edward I. But Edward had at least two daughters who married Continental noblemen, just for starts. ---
**Author:** ![Skald\_the\_Rhymer](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Skald\_the\_Rhymer](https://boards.straightdope.com/u/Skald_the_Rhymer)\ **Post date:** [April 1, 2011, 9:27pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/36 "2011-04-01T21:27:21Z")
> [@Bijou\_Drains](#): > > His future wife is a 14th cousin once removed. She is also related to George Washington and Guy Ritchie > > [http://www.cnn.com/video/#/video/world/2011/03/30/boulden.rw.kate.ancestry.cnn?hpt=C2](http://www.cnn.com/video/#/video/world/2011/03/30/boulden.rw.kate.ancestry.cnn?hpt=C2) And…? _Every woman in Europe_ is probably his fourteenth cousin. ---
**Author:** ![Dr.Drake](https://avatars.discourse-cdn.com/v4/letter/d/ad7895/32.png) [@Dr.Drake](https://boards.straightdope.com/u/Dr.Drake)\ **Post date:** [April 1, 2011, 10:03pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/37 "2011-04-01T22:03:44Z")
> [@septimus](#): > > Two caveats: > (1) My crude formula was intended more as an example of the indicated math, rather than an authoritative formula for this specific question. > (2) Your calculation seems to assume a zero chance that a non-Englishman (or non-Brit?) descends from Edward I. But Edward had at least two daughters who married Continental noblemen, just for starts. Don’t worry, I wasn’t taking that result as definitive. The whole point is that’s it’s interesting but ultimately not too meaningful to talk about descent from a common ancestor in the 14th century, whether you’re William or Kate or you or me. ---
**Author:** ![cochrane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cochrane/32/10441_2.png) [@cochrane](https://boards.straightdope.com/u/cochrane)\ **Post date:** [April 2, 2011, 5:56am UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/38 "2011-04-02T05:56:56Z")
> [@Nawth\_Chucka](#): > > As far as Royal marriages go, that’s very distant. Heck, Rudy Giuliani married a much closer cousin than that. Franklin Delano Roosevelt’s wife, Eleanor, was his fifth cousin, once removed. She was the niece of Theodore Roosevelt, who was FDR’s fifth cousin. They met at a White House reception in 1902, when T.R. was in office. ---
**Author:** ![Bookkeeper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bookkeeper/32/281_2.png) [@Bookkeeper](https://boards.straightdope.com/u/Bookkeeper)\ **Post date:** [April 2, 2011, 3:40pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/39 "2011-04-02T15:40:02Z")
Heck, even I’m more closely related than that, and that line of my ancestors left Britain in the late 1600s. ---
**Author:** ![antonio107](https://avatars.discourse-cdn.com/v4/letter/a/7ea924/32.png) [@antonio107](https://boards.straightdope.com/u/antonio107)\ **Post date:** [April 2, 2011, 3:53pm UTC](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621/40 "2011-04-02T15:53:58Z")
Ha! I knew he was a no good rotten Hillbilly. –sorry, HillWilliam. 😃 [Previous page](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621.md?page=1) [Next page](https://boards.straightdope.com/t/prince-william-marrying-a-distant-cousin/576621.md?page=3)