Harvard Law School Library has discovered that a document, previously misidentified as a copy of the Magna Carta purchased in 1946, is actually an original from 1300 issued by King Edward I, valued at millions. Researchers David Carpenter and Nicholas Vincent confirmed its authenticity through detailed analysis, noting it is one of the rare surviving originals and the last issued as a single sheet under royal seal. Carpenter expressed amazement at the find, emphasizing the significance of this document in world constitutional history.