Actually, it was more of a charter of the liberties of England's nobility... a peace treaty, really, because the English barons had Johnny over a barrel.
Yes, this is the same King John who was the evil prince in all the Robin Hood stories -- and he didn't improve after the end credits rolled on the Errol Flynn or even the Mel Brooks movies. Richard the Lion Heart left John with all of England and most of France in 1199 -- but John lost nearly all of France (including Normandy) in a series of wars, skirmishes and feudal missteps and, in the process, taxed his English barons into open revolt.
John lost this war, too, and Magna Carta, all 63 provisions (in Latin, of course) was the result. Only three of these provisions remain enshrined in English law today, according to the Salisbury Cathedral website (the Cathedral has one of the four remaining copies of the original 1215 document) but this one is important:
No free man shall be seized or imprisoned, or stripped of his rights or possessions, or outlawed or exiled. Nor will we proceed with force against him except by the lawful judgement of his equals or by the law of the land. To no one will we sell, to no one deny or delay right or justice.Of course, John had his fingers crossed when he signed the document and he broke faith with the barons about the same time he broke camp.
Fortunately, John managed to die about a year later and a Readers' Digest condensed version of Magna Carta (missing 25 of the original 63 clauses) was soon reproclaimed in the name of his 9-year old son, Henry III.
Meanwhile, the King of France invaded England (with the connivance of a good many barons who'd been fighting John) and conquered a good chunk of the country before giving up. Whereupon Magna Carta was again reissued, in 1217, with still more editing, and again in 1225, after Henry III managed to survive to adulthood. (One of the documents from 1217 is at England's Hereford Cathedral; some of the chronology referred to in this post, as well as the illustration at the top, comes from this linked site.) Magna Carta did not officially become a part of the laws of England in 1297 when an edition was reissued by Edward I (in exchange, of course, for a tax increase).
But, the bottom line is that none of this might have happened if King John had been less of an incompetent.
So tonight, lift your glasses high and toast the incompetence of our leaders -- the source of our cherished liberties.
Although that sounds wrong somehow, doesn't it?
If you insist upon an alternative, today is Separation Day in Delaware, commemorating that day in 1776 when one of King John's successors, George III, lost Delaware (it was on this day that Delaware proclaimed itself an independent state).