The Magna Carta, or Great Charter, is an English medieval document drawn up in 1215 by King John’s barons in feudal times. The barons were tired of having a king who could punish according to whim and the Magna Carta was a document that sought to curtail this power and give every freeman (non-serf) certain rights.
King John signed the document, although his intent was simply to bring the barons over to his side, as civil war was brewing and Prince Louis of France was threatening to invade. He had no intention of honouring the document. But after King John’s death in October 1216, the Magna Carta was copied and frequently used to show the sovereign was bound by law. Indeed, it has proved to be one of the most important civil rights movements in British history.
A 1297 copy of the Magna Carta has been preserved by the National Archives Conservation Lab by putting it in a case filled with the noble gas argon to prevent damage from oxidation. The case itself was hollowed out of a 15-centimetre (six-inch) block of aluminium in order to reduce creases through which the gas might leak.