What is meant by this medieval reference to combat 'under-ground'?

Underground meant fighting in a mine. The kind of mine that sappers dug to literally 'undermine' a wall. Defenders upon hearing the mine being dug would attempt to dig a countermine that intersected the mine. Either the countermine would be dug under the mine and then collapsed taking the mine above with it or it opened up both mines to each other. When this happened combatants from both sides could then engage in combat with each. Given the nature of the cramped conditions this often resulted in a duel.

Henry V during the hundred years war is noted as being such a duelist in a mine, taking part in underground duels at Harfleur in 1415 and Melun in 1420.

A little more at medievalists.net:

In a pit, for spectators.

I had an idea that "under" was an error converting the original Latin to English. I found the original

and chipped away at it some then thought to ask AlexP who participates in the WorldBuilding stack. His emailed answer to me is excellent in many ways. It would be a shame not to share the whole of it.

Willk 11:39 AM (8 hours ago) to AlexP

Hello AlexP. I hope all is well with you. Here is a diversion for me I thought might divert you as well.

middle ages - What is meant by this medieval reference to combat 'under-ground'? - History Stack Exchange

I had the idea that Stow's survey of London mistranslated the original. Or as seems more likely to me now, could not read it. I found the original here https://www.gla.ac.uk/myglasgow/library/files/special/images/chaucer/H215_0149rwf.jpg

You are full of surprising knowledge. Maybe some paleography? What do you read in the line after "tria duella"?

Best - WIllk

AlexP 4:11 PM (3 hours ago) to me

Hello William,

The text is from the Calendar of Letter-Books of the City of London, volume C, 1291-1309, folio c.xxx.iv. b. It is published online by British History Online (BHO), which is said to reproduce the edition published by Her Majesty's Stationery Office, London, 1901. I don't know about that edition. They say that they made the electronic edition by double rekeying from the 1901 printed edition, so the text should be somewhat trustworthy. Neverthelss, there are glaringly obvious transcription errors in the online version of the BHO, so it is unusable.

A good online copy of the 1901 edition edited by Reginald R. Sharpe and printed by order of the Corporation of the CIty of London under the direction of the Library Committee is available onlie at Archive.org as https://archive.org/details/ccalendarofletter00londuoft. In R. R. Sharpe's edition the relevant passage reads:

Temporilbus Knwti Regis Anglorum fuerunt tresdecim Milites regi et regno multum amabiles qui quandam terram in orientali parte London' ab incolis pro nimia servitute derelictam a rege pecierunt quatenus predictam terramn et Gilde libertatem imperpetuum eis concederet. Quibus Rex libenter concessit condicione qua sequitur videlicet quod quilibet eorum tria duella scilicet super terram subtus et in aqua victoriose perageret. Et postea certo die in campo qui rnodo vocatur Estsmithfeld contra quosque aduenientes ipsimet hastis decertarent quodque gloriose factum est.

meaning, as far as my rusty and always unreliable Latin goes,

In the time of Knuth King of the English, there were thirteen knights, much beloved by the king and the kingdom, who petitioned the king to concede to them in perpetuity and with Guild liberty a piece of land in the eastern part of London, which had been abadoned by the inhabitants because of the excessive obligations. To whom the King gratiously conceded [the request] on condition that any one of them win three duels, namely on land, below ground, and in water. And then in a certain field called Estsmithfeld the very same fought with lances against whoever came forward, which was gloriously done.

Coming specifically to the specific question, I read

quilibet eorum tria duella super terram subtus et in aqua

where rum, ter, and et are pretty ordinary scribal abbreviations.

OK, the ter abbreviation is maybe a bit unusual, but you can see the same word terram with the same bewildering appearance in the second line from the top: tis amabiles qui quandam terram in orientali parte: ter -- round -- script a bit squished - .

There is a statue of a knight in Devonshire Square in London, with a plaque which reads

King Edgar (959–75) granted this derelict land to thirteen knights, on condition that they each perform three duels, one on land, one below ground, one on the water. These feats having been achieved, the King gave the knights, or Cnihtengild, certain rights over a piece of land etc.

Or at least so says Flickr user Jim Linwood, who took a photograph of it in 2010. The photograph is available on Wikimedia under the Creative Commons Attribution 2.0 Generic license.

A bad PDF copy of Adriano Cappelli's canonical Elements of abbreviation in medieval Latin paleography (English translation by David Heimann and Richard Kay, 1982) is floating on the internet; for example, I found it at https://core.ac.uk/download/pdf/213385262.pdf

Ah, and I strongly believe that the "under ground duel" refers to a fight on foot, in a pit or a ditch; which pit or ditch could then be filled with water for the third duel. In this case, the first "above ground" duel would have been on horseback. The document says that the trial was held in an open field against all comers, and was gloriously done, which, I would say, means that onlookers could appreciate the sport, with the knights demonstrating a complete set of combat skills.

All the best, AlexP

Willk 5:13 PM (2 hours ago) to AlexP

Gloriose factum est! More than I could have hoped for, with additional references to look at and commentary on the hard-to-read writing. If I answer that question on history stack now it will be largely cribbed from your insights. Given how often that happens on WB stack one would think I would be ok with it. Sort of ok with with. But if you would like to post this as an answer that would be wonderful - it has everything I hoped my answer would have.

AlexP 5:26 PM (2 hours ago) to me

Hello,

I don't intend to post an answer on History SE. I do not participate to that Stack. If you want to, the please go ahead.

And I realized that I forgot to say that in that passage, per is also a scribal abbreviation. (Much more common that the ter.)

AlexP

It would make sense for a fight for spectators to be in a pit, so everyone could see. That is how they did with bear baiting and other blood sports, so it would make sense for a show duel too. I found references to the water duel as a sort of tilting but people would be in fast moving boats aiming for targets instead of on horseback. http://www.larsdatter.com/water-joust.htm