Una mensura sit per totum regnum nostrum

On Monday 15 June, the 800th anniversary of the signing of Magna Carta was celebrated in much of the English-speaking world. In this article we look at one of its less well-known clauses – that relating to weights and measures.

This introduction to Magna Carta appears in Wikipedia:

Magna Carta (Latin for “the Great Charter”), also called Magna Carta Libertatum (Latin for “the Great Charter of the Liberties”), is a charter agreed by King John of England at Runnymede, near Windsor, on 15 June 1215. First drafted by the Archbishop of Canterbury to make peace between the unpopular King and a group of rebel barons, it promised the protection of church rights, protection for the barons from illegal imprisonment, access to swift justice, and limitations on feudal payments to the Crown, to be implemented through a council of 25 barons. Neither side stood behind their commitments, and the charter was annulled by Pope Innocent III, leading to the First Barons’ War. After John’s death in 1216, the regency government of his young son, Henry III, reissued the document, stripped of some of its more radical content, in an unsuccessful bid to build political support for their cause. At the end of the war in 1217, it formed part of the peace treaty where the document acquired the name Magna Carta … . Short of funds, Henry reissued the charter again in 1225 in exchange for a grant of new taxes; his son, Edward I, repeated the exercise in 1297, this time confirming it as part of England’s statute law.

Wikipedia adds:

The original charters were written on vellum sheets using quill pens, in a particular style of abbreviated Latin. Although academics refer to the 63 numbered “clauses” of Magna Carta, this is a modern system of numbering … the original charter formed a single, long unbroken text.

So what has this to do with the UK’s adoption of metric measures?

The Charter went beyond simply addressing individual baronial complaints, and formed a wider proposal for political reform, as noted above. Furthermore, it sought to resolve a number of popular grievances identified by the rebel barons, whose support increased accordingly, for example:

Clause 23. No village or individual shall be compelled to make bridges at river-banks, except those who from of old were legally bound to do so.

Clause 33. All kiddles (fish weirs) for the future shall be removed altogether from Thames and Medway, and throughout all England, except upon the seashore.

And yes,

Clause 35. Let there be one measure of wine throughout our whole realm; and one measure of ale; and one measure of corn, to wit, “the London quarter;” and one width of cloth (whether dyed, or russet, or “halberget”), to wit, two ells within the selvages; of weights also let it be as of measures.

Latin scholars will recognise the title of this article in this clause.

Only three of Magna Carta’s 63 clauses survive in English law today, and these do not include any of those quoted above. However Magna Carta still forms an important symbol of liberty, often cited by politicians and campaigners, and is held in great respect by the British and American legal communities, having been described as “the greatest constitutional document of all times – the foundation of the freedom of the individual against the arbitrary authority of the despot”.

And clause 35?

This clause did not end the tendency of measures in England and elsewhere to proliferate  – there always have been and always will be those who aim to profit from measurement confusion. But it established a principle, and an indication of its success is that measurement was not an issue during the political upheavals Britain and Ireland experienced in 1645-49 and in 1688. This is in contrast to the situation in France as outlined by Ken Alder in his book, “The measure of all things”. He writes:

“One Englishman, travelling through France on the eve of the Revolution, found the diversity there a torment. ‘In France,’ he complained, ‘the infinite perplexity of the measures exceeds all comprehension. They differ not only in every province, but in every district and almost every town …’ Contemporaries estimated that under the cover of some eight hundred names, ancient regime France contained a staggering 250 000 different units of weights and measures.”

So the rebel barons got it right. In 1215, here was an issue of popular concern and political significance. Which makes the UK’s tolerance 800 years later of a monumental measurement muddle both surprising and understandable.

12 thoughts on “Una mensura sit per totum regnum nostrum”

  1. American view here, but it affected us profoundly. Clause 35 is a problem: “Let there be one measure of wine throughout our whole realm; and one measure of ale; and one measure of corn.” These are three measures of volume (and two were liquids); you solved it with Imperial, we never did. It established a precedent that as long as the measurement was for a different purpose, it was OK to use a different measure, just not in different places. Why did you (previously) use different gallons for ale and wine, each of which had its bushel 8X larger and neither equal to the corn bushel? We unfortunately never fixed it and have a liquid gallon and dry bushel with no sensible integer relationship (they are as 231 is to 2150.42). Among the submultiples we have both liquid and dry pints and quarts; even we are thoroughly confused by that, imagine the rest of the world.

    In this context, it is not surprising you use pints for beer and litres for all other liquids or feet and miles on roads and metres for all other lengths. It is not your fault we never reconciled our (formerly, your) gallons and bushels, but I think it speaks to both our measurement muddles.


  2. The idea of one measure makes sense. As a result, England had a uniform set of weights and measures long before any other nation in Europe. The downside of this was that when the metric system was developed in France, the British did not feel so inclined to switch to it.

    However, we now have the annoying situation where there are two systems running side by side for a whole raft of measures. Land is described in both acres and hectares. People’s weight is described both in kilograms and stones and pounds. There are metres and yards, centimetres and inches, and miles (one for the sea and two for the land) and kilometres. There are long tons, metric tonnes and short (American) tons. Car tyre diameters are in inches and their width in millimetres! Screens are measured by the diagonal in both inches and centimetres instead of being measured according to surface area. There is fuel sold by the litre but fuel economy measured in miles per Imperial gallon. There is milk sold by the pint and by the litre. Celsius, though, has largely displaced Fahrenheit.

    The curious thing about the confusion is the number of people who think this is OK, or part of British heritage. From the inside it might seem to be normal; from the outside it appears to be crazy!

    What then is to be done? The political parties appear to have no stomach for further reform and there are people whose life work appears to be to fight metrication every inch of the way. Even so, metric measures are making a slow advance. I believe that quiet lobbying can encourage this transition. Letters to public officials along the lines of “why are you using feet and yards when Buckingham Palace is described in metres” can have an effect.


  3. @Michael Glass
    Thanks for the interesting information.
    I now only buy milk if it’s in litre containers! (My new policy).


  4. Gosh Rob. Just watch the prices per litre, however. I’d hate you to be ripped off!


  5. It’s doubly ironic that the Pubs Minister (do we really have a minister for pubs?) chose beer as a subject for an official Government press release about the 800th anniversary of Magna Carta.


    Not only is beer sold in units from more than one measurement system (imperial for draft, and metric for bottled beer), and as such clearly contravenes the intention of Magna Carta which stipulates that there should be just one measurement system throughout the land.

    But also, he (or his advisers) has confused the London Quarter (equivalent to 8 gallons, or 64 pints – according to wikipedia) with the imperial quart (2 pints), thus further supporting the case for a single easy-to-understand measurement system.


  6. Jake says: 2015-06-16 at 10:36
    § M
    Methinks the Minister needs to be told!

    Methinks there is none so blind as those that do not want to see.

    There is a link at the bottom of the page “Is there anything wrong with this page?”

    However, my view is turning more to let them all revel in their own stupidity. It is now only a matter of time before some minister, or other senior official trips up real big time.

    You and I will change nothing, they do not want to know, they do not want to hear, they do not see and they certainly do not want to do anything about it. They will just prattle out with the official government clap trap.


  7. “Latin scholars will recognise the title of this article in this clause.”

    Hmm, considering that a number of obsolete imperial units are Italian in origin, and that SI is the way forward, I wonder if resorting to Latin, a totally dead language, is sending out the right message?


  8. The Community Pubs minister Marcus Jones reportedly said “I am told that in medieval times a standard measure of beer was the equivalent of 2 pints – called the London quarter – so while our glasses may now be smaller, our love for British beer remains as great as ever.” However, according to Wikipedia (https://en.wikipedia.org/wiki/Quarter_(unit) ), the “London quarter” (of corn) eight bushels, each of eight gallons (about a quarter of a ton). Somebody, somewhere got their facts facts wrong!


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