PS,
Many of Shakespeare's plots (sometimes even lines of dialog)were recycled from older works, too. "Hamlet" is ripped off from the older (and very popular) "The Spanish Tragedie" by Thomas Kyd, and he got "Julius Caesar" from the Romans. And of course, "Forbidden Planet" is a direct steal from W.S.' last play, "The Tempest".
In those days, before "intellectual property" laws and copyright lawyers, borrowing from and improving on, another author, even a well-known one, was considered an homage, not plagiarism. The audience wasn't fooled, they were quite sophisticated. It would be like a modern band covering a Beatle or Stones tune, but putting their own spin on it. Except there were no royalties.
"Intellectual property" is an oxymoron,