Is Karl Marx’s Great-Great-Grandson Really Doing Parkour in London?

Earlier today, I stumbled across this Quora answer by Eric Wang about a teenaged parkourist named Joseph Marx who lives in London and claims that he is the great-great-grandson of Karl Marx. The story was so bizarre and yet so awesome that I started looking around on the internet to see if I could find out more. I uncovered at least half a dozen articles online talking about it.

Despite how intriguing I found this story, I very quickly became skeptical of it because I noticed that some of the details didn’t seem to fit. I have always had an interest in reading about living descendants of famous historical figures and I had a bit of time on my hands, so I decided to investigate this claim.

I can’t prove for certain that this Joseph Marx is not a descendant of Karl Marx, but, having now charted all Karl Marx’s known descendants, I’m 90% convinced that Joseph Marx is just some guy who happened to have the same last name and incorrectly assumed that Marx was his great-great-grandfather without any solid evidence.

Why I was initially skeptical of this story

The first reason why I was skeptical of the story about the London parkourist was because I remembered that Karl Marx only had three children who survived to adulthood and they were all daughters with the first name “Jenny.” It therefore struck me as strange that his great-great-grandson would have the last name Marx, because, normally, last names are passed down through the male line.

It also struck me as strange that Marx was born in 1818, but yet this Joseph Marx fellow who claimed to be his great-great-grandson was only a teenager. If you do the math, you realize that, at some point, some of Marx’s descendants would have had to have had children at an unusually advanced age in order for his great-great-grandson to be so young.

Finally, I was also skeptical of just how disinterested Joseph Marx seemed to be in political theory. An article about him published in the Surrey Comet says this:

“Mr Marx says he flirted with his great-great-grandfather’s socialist ideals, but ultimately decided that they did not work in practice. Kingston’s McDonald’s has been the group’s base.”

A real great-great-grandson of Karl Marx would have almost certainly grown up with his parent (i.e. Marx’s great-grandchild) talking about Marxism around the house. Marxism wouldn’t just be something he “flirted” around with; he would either be a hardcore Marxist himself or have a much stronger reason for rejecting Marxism than simply “It wouldn’t work in practice.”

ABOVE: Photograph from this article from the Surrey Comet about Karl Marx’s alleged great-great-grandson and his parkour group

Karl Marx’s three daughters: Jenny, Jenny, and Jenny

Because I was suspicious, I decided to go back to the sources and attempt to trace the line of descent from Karl Marx himself to the parkourist in London who claims to be his descendant. To do this, I began researching Marx’s known descendants.

Karl Marx and his wife Jenny von Westphalen had seven children altogether. Tragically, though, only three of them survived to adulthood: Jenny Caroline Marx (lived 1844 – 1883), Jenny Laura Marx (lived 1845 – 1911), and Jenny Julia Eleanor Marx (lived 1855 – 1898).

Jenny Julia Eleanor committed suicide on 31 March 1898 after she discovered that her partner Edward Aveling had secretly married an actress the previous summer. She never married and she never had any children. Jenny Laura and her husband Paul Lafargue committed suicide together on 25 November 1911. They never had any children either.

Thus, of the seven children Karl Marx sired, only his eldest daughter Jenny Caroline ever had any children of her own. She married a political activist named Charles Longuet on 10 October 1872. Together, they had six children. Their eldest son Charles Felicien Longuet died of diarrhea before he was even a year old, but their five other children survived to adulthood: Jean-Laurent-Frederick Longuet (lived 1876 – 1938), Henri-Michel Longuet (lived 1878 – 1938), Edgar Longuet (lived 1879 – 1950), Marcel Longuet (lived 1881 – 1949), and Jenny Longuet (lived 1882 – 1952).

ABOVE: Photograph from 1870 of Karl Marx’s eldest surviving daughter Jenny Caroline and her husband Charles Longuet

Karl Marx’s great-grandchildren and great-great-grandchildren

Here is the breakdown of all Karl Marx’s known great-grandchildren:

• Jean-Laurent-Frederick Longuet had three sons: Robert-Jean Longuet (lived 1901 – 1987), Karl-Jean Longuet (1904 – 1981), and Frederick Longuet (dates unknown).
• Edgar Longuet had four children: Jean-Paul Longuet (lived 1909 – unknown), Charles Longuet (dates unknown), Frederique Longuet (dates unknown), and Jenny Longuet (dates unknown).
• Marcel Longuet had one son: Marcel-Charles Longuet (dates unknown).
• As far as I can tell, neither Henri-Michel Longuet nor Jenny Longuet ever had any children.

Unfortunately, there seems to be very little verifiable information publicly available about Karl Marx’s great-great-grandchildren or their descendants. One thing we do know is this: On 18 September 1954, The New Yorker published an interview with Robert-Jean Longuet. The preface before the interview states that, at that time, there were only thirteen living descendants of Karl Marx. We can probably assume that this number is accurate, since presumably Robert-Jean Louguet was in a position to know how many relatives he had.

The interview was published shortly after the death of Jenny Longuet, Marx’s last surviving grandchild. If we add up Jean-Laurent-Frederick Longuet’s three sons, Edgar Longuet’s two sons and two daughters, and Marcel Longuet’s one son, we get a total of eight descendants, meaning there must be five other descendants who were alive in 1954 who are not accounted for. These are most likely the oldest of Karl Marx’s great-great-grandchildren.

ABOVE: Photograph of Robert-Jean Longuet (lived 1901 – 1987), the eldest son of Karl Marx’s grandson Jean-Laurent-Frederick Longuet

I was able to find that Karl-Jean Longuet (i.e. the second son of Jean-Laurent-Frederick Longuet) married the sculptor Simone Boisecq and, together, they had two daughters: Frédérique and Anne, both of whom are still alive. Frédérique was born in 1955 and Anne was born in 1958. At some point, they apparently changed their name to “Longuet-Marx” to emphasize their relationship to Karl Marx.

From what I can gather, Frédérique and Anne Longuet-Marx both currently live in France. In May 2018, they participated in the opening of a new exhibit about their great-great-grandfather Karl Marx at the house where he was born in the city of Trier in honor of his two hundredth birthday. (Here is an article about the event in German.)

I cannot find any reliable information about Karl Marx’s other great-great-grandchildren, but most of Marx’s great-grandchildren were men and all of them had the last name Longuet, meaning most of his great-great-grandchildren should have at least been born with Longuet as their last name.

Things are made a bit more complicated, though, by the fact that Edgar Longuet had two daughters, meaning we have no way of knowing what last names their descendants may have, since, if they chose to marry, they presumably would have taken the last names of their husbands.

ABOVE: Photograph taken in May 2018 of Frédérique and Anne Longuet-Marx posing next to a statue of their great-great-grandfather Karl Marx made by their father, the sculptor Karl-Jean Longuet

A more likely scenario

None of Karl Marx’s descendants should have the last name “Marx,” unless they changed their names to “Marx” to highlight the fact that they are descended from Karl Marx. While it is possible that Joseph Marx or his parents may have done this, it seems far more likely to me that Joseph simply noticed that he had the same last name as Karl Marx and incorrectly assumed that he was his great-great-grandson.

Perhaps the most compelling piece of evidence that leads me to this conclusion is the fact that Karl Marx’s last surviving grandchild, Jenny Longuet, died in 1952 at the age of about seventy. In order for Joseph Marx to be her grandchild, his parent would have had to have been born in the 1920s or 30s, which would make his parent around ninety years old right now—even though Joseph is only a teenager.

Edgar Longuet died in 1950 at the age of seventy-one and Marcel Longuet died in 1949 at the age of sixty-eight. Men can still have children in their sixties, so, if Edgar or Marcel Longuet were Joseph Marx’s grandfather, that would at least open up the possibility that Joseph’s parent could have been born in the 1940s, which would mean his parent would be currently in their seventies.

Nonetheless, this would still require two cases of people having sired children at remarkably advanced ages, because it would require Edgar or Marcel Longuet to have had Joseph’s parent when he was in his sixties and Joseph’s parent to have had him when they were in their fifties.

I am convinced that the most parsimonious explanation here is that Joseph isn’t related to Karl Marx at all and that he just wrongly assumed that he was based on his last name. Marx is actually a fairly common last name and most people who have it aren’t closely related to each other. For instance, Karl Marx is of no discernable familial relation to the Marx Brothers, the group of comedian brothers that became popular in the United States in the early twentieth century.

Likewise, neither Karl Marx nor the Marx Brothers are in any way related to the German musicologist Adolf Bernhard Marx (lived 1795 – 1866), to the German physician Karl Friedrich Heinrich Marx (lived 1796 – 1877), to the German composer Karl Marx (lived 1897 – 1985), or to the American pianist Bill Marx (lived 1937 – present).

Having the same last name as someone doesn’t necessarily mean you are of any close relation to them.

ABOVE: Photograph from 1921 of the Marx Brothers. Karl Marx and the Marx Brothers have the same last name, but they aren’t related in any other way.

Addendum, added on 23 January 2021

It has been over half a year since I originally published this article. Joseph Marx himself has now reached out to me and informed me that he never actually claimed to be a descendant of Karl Marx and that the whole story about him supposedly being Karl Marx’s great-great-grandson was entirely made up out of whole cloth by the local newspaper just to attract attention.