Illuminating History's Most Obscure Corners | Issue #38 | June 2026
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It is June 1215, and King John of England is having a very bad week.
This is the same King John immortalized as a thumb-sucking, tax-obsessed lion in Disney's 1973 Robin Hood. History has not been generous.
The barons are done with him. Done with the arbitrary imprisonment, the extortionate taxation, the seizure of estates, the general sense that the king might do anything to anyone at any time and there was no mechanism to stop him. They have raised an army. They have taken London. And now they are standing in a field at Runnymede, on the Thames between Windsor and Staines, handing him a piece of parchment and suggesting, with the weight of drawn swords behind the suggestion, that he sign it.
He signs it.
The document is called Magna Carta — the Great Charter. It runs to 63 clauses. Most of them are spectacularly tedious. There are clauses about fish weirs on the Thames. Clauses about the debts of Jewish moneylenders. Clauses about how long a widow must wait before being compelled to remarry. Medieval bureaucracy in full flower.
But two clauses are different.
Clause 39: no free man shall be imprisoned, dispossessed, or harmed except by the lawful judgment of his peers or by the law of the land. Clause 40: to no one will we sell, to no one deny or delay, right or justice.
Due process. Equal justice. Two sentences that will travel across eight centuries and end up in the United States Constitution, invoked by everyone from 17th century parliamentarians to 21st century lawyers filing briefs on behalf of Guantanamo detainees.
John signs the charter on June 15th. He begins working to destroy it on June 16th.
He writes immediately to Pope Innocent III, his nominal feudal overlord, explaining that he has signed under duress and requesting annulment. Innocent — who had his own reasons for keeping English kings pliant — responds with remarkable speed. By late August, barely ten weeks after Runnymede, he issues a papal bull declaring the charter "shameful, demeaning, illegal, and unjust." Void. Gone. As if it never happened.
Civil war breaks out almost immediately. The barons invite the French prince Louis to take the English throne. John spends the autumn of 1216 fighting a war on two fronts, losing his baggage train — including, allegedly, the crown jewels — to a tidal flood in the Wash estuary, and then dying of dysentery in October.
He is succeeded by his nine-year-old son.
Henry III cannot fight a civil war. His regents can barely hold the kingdom together. What they can do is buy support, and what the barons want, it turns out, is the charter — a revised version, stripped of its most inconvenient enforcement mechanisms, but recognizably the same document John had signed and the Pope had annulled.
So they reissue it. Not out of principle. Out of necessity. A child king's regents, making a political deal to survive.
They reissue it again in 1217. Again in 1225. Each time slightly different, each time a little more settled into law. By 1297, Edward I issues it one final time and enters it into the official statute rolls of England. It is now, formally and permanently, the law of the land.
Nobody is entirely sure what it means anymore.
This turns out to be its greatest asset.
The charter spends most of the next three centuries as background furniture — present, respected, occasionally cited, not particularly transformative. Then the 17th century arrives, and with it a constitutional crisis that needs a foundation.
When parliamentarians square off against Charles I in the 1620s, they reach for Magna Carta. Sir Edward Coke, the great jurist and parliamentary champion, argues that the charter is the ancient bedrock of English liberties — that Clause 39's guarantee against arbitrary imprisonment is not a medieval barons' privilege but a universal right of every Englishman. He is, historians will later note, substantially rewriting what the document actually said. The barons of 1215 were protecting themselves, not abstracting a principle.
It doesn't matter. The rewrite sticks.
Charles I is eventually beheaded. Parliament wins. And the idea that no government may imprison a person without lawful cause — habeas corpus, as it will come to be formalized — becomes a cornerstone of English constitutional thinking.
It crosses the Atlantic in the minds of colonists who carry English common law with them.
By the 1770s, the American founders are steeped in Coke's interpretation of Magna Carta. When they write the Fifth Amendment — "no person shall be deprived of life, liberty, or property, without due process of law" — they are consciously reaching back to Clause 39. The phrase due process of law is a direct translation of the Latin per legem terrae, by the law of the land, from the 1354 restatement of the original charter.
The Fourteenth Amendment, ratified in 1868, extends the guarantee to the states: no state shall deprive any person of life, liberty, or property without due process. This is the clause that will eventually be used to incorporate most of the Bill of Rights against state governments, to establish the right to contraception, to strike down school segregation, to recognize same-sex marriage.
All of it, in a direct line, from a document signed in bad faith by a king who was already writing to the Pope to have it annulled.
The last chapter is almost too good.
In 2004, lawyers representing detainees held at Guantanamo Bay argue before the United States Supreme Court that their clients have the right to challenge their detention in federal court. They win. The majority opinion in Rasul v. Bush traces the right to judicial review back through centuries of English common law to Magna Carta.
Eight hundred and eighty-nine years after John signed it under duress in a field by the Thames, the charter is still working.
He would be furious.
Only four copies of the 1215 Magna Carta survive. One is held at Salisbury Cathedral, one at Lincoln, and two at the British Library. In 2007, one of the British Library copies was nominated as a UNESCO Memory of the World document. The fish weir clauses have not been invoked in some time.
What's Next in Obscurarium?
What bizarre historical phenomenon should we investigate next? Drop us a line at [email protected].