A copy of the Magna Carta was sold at auction Tuesday evening for $21.3 million to David Rubenstein, the founder of a private equity firm.
Rubenstein plans to keep the handwritten English charter at the National Archives, where it's been on display for years.
The agreement signed in 1215 between King John and rebellious English barons mentions things like the right to a trial and the idea that no one is above the law. It's considered one of the most important legal documents in the history of democracy.
There are 17 versions of the handwritten English charter in the world. Only two copies exist outside England: one in Australia and the one auctioned off Tuesday at Sotheby's in New York City.