Original Magna Carta copy discovered in Harvard University archives

An original copy of the Magna Carta has been discovered hiding in the archives of Harvard University, and the British medieval history professor who first stumbled across it online said the document is "one of the world's most valuable."

The 19-inch-by-19-inch parchment document is part of the Harvard Law School Library's collection of fragile documents and artifacts and was purchased by the university for $27.50 from a British auctioneer nearly 80 years ago.

The document has been on display in a case at the library and digital images of the document have been available online to researchers and medieval memorabilia buffs for years.

Until now, the law library staff just figured it was a cheap knockoff, said David Carpenter, the professor of medieval history at King's College in London, who made the astonishing discovery.

Carpenter said the document had been miscatalogued by the auction house where the university purchased it as dating to 1327, and describing the manuscript as "somewhat rubbed and damp-stained."

"They bought it for peanuts in 1946 from an auctioneer, Sweet & Maxwell, who clearly seemed to have no idea what it was," said Carpenter.

Carpenter told The Associated Press that he was researching Harvard Law School's digitized historical documents collection online for a book in 2023 from his home in southeast London when he clicked on a document marked "HLS MS 172."

"I immediately thought, 'Oh my God,'" said Carpenter.

He said he recognized the document as one of just seven original copies still in existence of the Magna Carta issued in 1300 by Britain's King Edward I.

He said the university's library staff thought it was just a cheap copy that no one paid that much attention to, even when it has been put on display in the library.

"My reaction was one of amazement and, in a way, awe that I should have managed to find a previously unknown Magna Carta," Carpenter said.

The first Magna Carta was issued in 1215 by England's King John, declaring that the king and his government were not above the law and outlined the legal rights of commoners for the first time. Five subsequent updated editions of the document were issued, including the one issued by Edward I. The document has since influenced the writing of the U.S. Constitution and constitutions around the world.

"It's one of the world's most valuable documents," Carperter told Harvard Magazine in an article published on Thursday.

A copy of the Magna Carta issued by King Edward I in 1297 sold for $21.3 million at a Sotheby's auction in 2007.

Carpenter said that after he recognized that the rarest of rare documents was at Harvard, he contacted Nicholas Vincent, a professor of medieval history at the University of East Anglia in Norwich, England, and a Magna Carta expert, asking him to help authenticate the document.

Vincent told Harvard magazine that he immediately called the Harvard Law School Library, informing them of what was right under their noses.

"I think they may have thought that I was a lunatic, actually," Vincent told the magazine.

The library staff eventually worked with Vincent and Carpenter to help authenticate the document. Using ultraviolet light and spectral imaging technology, the scholars said they found telltale details not visible to the naked eye.

"At a time when state authorities are doing strange things, it’s a very timely reminder that the rule of law governs the governors, as well as the governed," Vincent said.

Harvard Law School librarians told Harvard magazine that the document is now in a vault with other rare artifacts and might be displayed at future law school events.