#i also feel like warner's practice of looking at the ipm and going 'oh it gives a date therefore it's the most accurate and reliable entry'

[heartofstanding]

Joan of Kent's age

When I was writing up this post on Joan of Kent, I got curious about the question of Joan's age. The year that's typically given is 1328 but Kathryn Warner has argued that it was actually 1326 or 1327, based on the Inquisition Post Mortem for Joan's brother, John, made in 1352. Two entries in the IPM give her age as "25 years and more at St Michael last" and "26 years and more at St. Michael last". Warner concludes that as these two entries are the only ones that give a date - St. Michael being Michaelmas or 29 September - around which Joan's birthday must have fallen, then they must have the correct age for Joan, and then concludes:

Where does that [1328] date come from?  Did someone perhaps once see John's IPM and mess up the maths and think that age 25 or 26 subtracted from 1352 equalled a date of birth in 1328, and everyone else has just copied it ever since without checking?  Or is there some other evidence somewhere I'm missing?

Have historians just being repeating someone's bad maths for decades, too dumb to check the source? Well, no. Come with me on a journey of statistics.

My first thought was Joan's age might have been given in the documents relating to her marriages - which are helpfully transcribed in the appendices of Karl P. Wenterdorf's article on Joan's marriages. Except these only say that Joan was of marriageable age when she married Holland. The canonical age of consent for girls was 12 so Joan would have at least 12 when she married Holland, which would make her born at the latest in 1328. But it didn't make sense that historians would pick this when the reference is so unspecific and Warner is so convinced that the IPM gave us a clearcut answer.

On a whim, I checked out the IPM myself and stopped. The first entry gave her age as "24 years and more". I started scrolling. The answer became obvious. The IPM gives a range of ages from 22 to 26 years and more, which Warner dismisses by claiming the juries would not have never met Joan or know when she was born and just picked random on the basis that all they knew was that she had to be born between 1326 and 1330. But since two give a date around which she could be said to be "25/26 years and more", one of these, according to Warner, must be the correct date of birth.

But the 1328 date comes from the IPM, clear and simple. It is not based on the same logic that Warner uses and it is not a case of "messing up" the maths. It's statistics. Basic statistical analysis.

There are 19 entries that give Joan's age, plus three more that say only "heir as above" [1]. Her age given ranges from 22 to 26, given in turn would mean her birth year ranges from 1326 to 1330. Giving her age as 24 and her birth year as 1328 would put her in the middle of that range. 1328 is also suggested by the frequency by which the age "24 years and more" is given - ten entries out the nineteen entries give that age. Over half. The second-most frequent entry is "26 years and more" at five entries, half that of the entries that give her age as 24 [2]. 22 years and more is given twice. 23 years and more and 25 years and more are only given once each. Here is a chart showing the frequency.

([1] The entries above these give her as 25 years and more once and 24 years and more twice. I have not included these entries in the tally of entries for 24 or 25 years. If I did, the number of entries of 25 years and more would rise to 2 and for 24 years and more, 12. [2] one of the entries that give her age as 26 gives it as "26 years and not more". Rather that counting it separately, I combined it with the "26 years and more".)

The average age based on these entries is 24.3 years of age.

We can narrow Joan's date of birth down further. Her father, Edmund Earl of Kent, was executed on 19 March 1330 and her brother, John, was born just under a month later, on 7 April 1330. Joan is said to have assisted at his baptism so she cannot have been his twin and cannot have been born in 1330. If her birthday did fall around 29 September, she cannot have been born in 1329 either as her mother would have been pregnant with John then. 1328 is the latest year she could be born in, assuming the September birthdate is correct. We don't know when the elder of her two brothers, Edmund, was born only that he had died before October 1331 and like Joan, was a godparent to their younger brother.

Joan's parents married in December 1325, meaning September 1326 is the earliest any child could be born - though this assumes the child was not the result of pre-marital sex. Pre-marital sex was not exactly an uncommon feature in medieval marriages so it is a possibility.

Warner cites another piece of evidence for disregarding the 1328 birthdate. John's proof of age reports:

Edmund son of the said Edmund [Earl of Kent], and Brother John de Grenstede, prior of the order of Friars Preacher of Arundel, and Joan, sister of the said Edmund son of Edmund, lifted the said John from the sacred font on 7 April, 4 Edward III…

Warner concludes that if Joan was born in 1328, it is unlikely that at 18 months, Joan would be considered "old enough and big enough and responsible enough" to lift her newborn brother from the font, even with adult assistance. Maybe, but a similar issue would apply if Joan was 2.5 years old. Perhaps, too, the proof of age should not be read as an exact statement of what happened at John's baptism and the exact wording of Joan "lifting" her newborn brother as a standard turn of phrase than a perfect description of what she did. Both Joan and Edmund would've needed the assistance of adults to act as godparents, though the proof of age does not mention this either. Warner points out that the earliest a child could have been born to their parents was September 1326, which means at either child could be, at most, 3.5 years old. A 3.5 year old wouldn't have been tall enough to reach the font on their own - especially once we take into consideration the forensic evidence that medieval children developed physically slower than modern children.

Another factor, unmentioned by Warner but pointed out by Penny Lawne, is that the direness of the family's situation meant that the newborn John's siblings were playing a very unusual role. Small children were not the typical choice for godparents. This was, after all, just under a month since Edmund, Earl of Kent had been executed and it's likely they were under some kind of house arrest at the time. Edmund and Joan were likely the most suitable choice around - John's other godfather was a prior, a "modest choice" given the family's status. If Joan was 18 months old, it may simply reflect that the family had little alternative.

It is true that two entries in the IPM give Joan's age as "25/26 years and more at St. Michael last." which has generally been taken to suggest Joan was born on or around the feast of St. Michael, i.e. 29 September. Warner assumes that because these two entries are the only ones to be specific about the date, they must be better informed about Joan's birth year.

However, the fact that neither agree on her age suggest that they are not wholly reliable. Furthermore, Warner does not suggest why the locations where this IPM was carried out (Leicester and Nottingham) should be so well informed about Joan's birth and the rest not. We do not know where Joan was born or any details of her birth, such as her godparents, to know if she was born in those locations (Warner herself suggests that if the 1326 date is correct, it's likely Joan was born overseas - which would suggest her birthdate would be incredibly obscure). Nor does it seem like her own proof of age survives to give us these details, or else Warner or Lawne would have cited it.

Warner's final piece of evidence for suggesting that Joan was "rather older" (two years older) and born in 1326 or 1327 is that it would make her "13 or 14" when she married Thomas Holland, as opposed to 12 years of age which is more in keeping with modern sensibilities. Actually, given her birthday was in September and she married Holland in or before May 1340, she would have been 13 at most. Such an argument has no basis in surviving evidence or fact, it is about making modern people more comfortable with the reality of Joan's life. A better argument is that if Joan was born in 1328 the claim made in Holland's petition to the pope that she was of "marriageable age" when they married would be factually incorrect as she would only around 11 years and 8 months old and not yet the canonical age of consent - 12. However, it is possible that Holland fudged the claim and rounded Joan's age up for the purposes of his claim.

*

I don't really know what to think now. I was fairly convinced by Warner's argument that Joan must have been born in 1326 or 1327 but seeing for myself how frequent the age of 24 years is given makes me feel that the 1328 may be far more likely than Warner believes. The theory Warner suggests - that the juries simply guessed at when Joan could be born and came up with a random number - does not readily explain why over half of the juries should randomly pick 24 years of age - double the number of the juries who picked 26 years of age, and ten times the number of the juries who picked 25 years of age. In the end, I do not think the 1328 birthdate can be so readily dismissed - I would say that Joan could have been born in 1326, 1327 or 1328, and unless more evidence is discovered, we will never a definitive answer.