I recently came across the strange story of an unusual brand of criminal - a literary forger. He committed his crimes almost two centuries ago and yet, oddly enough, you may be familiar with some of his work.
John Payne Collier* (1789-1883) was an English journalist and drama critic, with a somewhat erratic career. His incorrect report on a speech by a member of Parliament had him chastised by the House of Commons. It took him eighteen years to be called to the bar because of a book he wrote criticizing lawyers.
With that promising start he dove into scholarship on Shakespeare. His critics found much to complain about in his work but generally found it valuable. In 1847 he became secretary to the Royal Commission on the British Museum.
Five years later he claimed to have discovered a copy of the Second Folio, the 1632 collection of Shakespeare's plays. His copy was called the Perkins Folio because of a name inscribed on the title page. Any copy of that book would be considered important but this one was full of handwritten annotations and corrections, apparently in a seventeenth century hand. A remarkable find!
Collier published a book of the annotations and later put out a new edition of Shakespeare with the Perkins version of the text.
You've probably guessed that this didn't end well. A scholar/friend of Collier's described the changes in the Perkins Folio as "ignorant, tasteless and wanton." By 1859 scientists had proved that the annotations were modern scribblings in the old volume. No one could prove that Collier had done the deed and he was, remarkably, allowed to continue to publish scholarship. No cancel cuture then!
His other works included dubious lecture notes by Coleridge, forged additions to old letters, spurious annotations supposedly written by Milton, and so on. Nonetheless he also produced scholarship the professors found useful, when he could find sources to work from. It appears that, like not a few modern scientists, when he couldn't find the results he wanted he made them up.
I have taken most of this information from the Wikipedia article and the anonymous authors/editors there said: "No statement of his can be accepted without verification, nor any manuscript handled by him, without careful examination, but he did much useful work."
But remember I said that you might be familiar with some of his work. Here's the deal: In 1828 he published The Tragical Comedy or Comical Tragedy of Punch and Judy. While the Punch and Judy show traces its origins to the 16th century Italian comedia dell'arte, Collier's is the earliest existing script for it. To some extent every modern "professor" (the traditional name for the P&J puppeteer) is improvising from Collier's text.
He claimed to have copied it down from a performance by an Italian puppet master, and maybe he did. But he was as untrustworthy as Mr. Punch himself, so how can we know?
* Not to be confused with the great and more recent John Collier.