Czech researcher used AI to find Shakespeare only wrote half of Henry VIII

British playwright William Shakespeare gets all the credit for his plays, but he had help on a some of them. A Czech researcher used an artificial intelligence algorithm to see just how much help he had on Henry VIII, one of his later efforts. It turns out that Shakespeare only wrote about half of the play, and the rest was by another writer named John Fletcher.

Petr Plecháč of the Czech Academy of Sciences fed undisputed works of both playwrights into a machine learning algorithm so it could learn phrases and patterns distinctive to each author. From Shakespeare, he used Coriolanus, Cymbeline, The Winter’s Tale, and The Tempest. Fletcher’s works were Valentinian, Monsieur Thomas, The Woman’s Prize, and Bonduca.

“The versified play Henry VIII is nowadays widely recognized to be a collaborative work not written solely by William Shakespeare. We employ combined analysis of vocabulary and versification together with machine learning techniques to determine which authors also took part in the writing of the play and what were their relative contributions,” Plecháč said in the abstract for his research paper called “Relative contributions of Shakespeare and Fletcher in Henry VIII: An Analysis Based on Most Frequent Words and Most Frequent Rhythmic Patterns.”

Plecháč also looked into a theory that playwright Philip Massinger, who also wrote plays for the King’s Men troupe that Shakespeare belonged to, had a hand in Henry VIII. The analysis did not find any evidence of that.

Henry VIII, or as it is called in early printings, The Famous History of the Life of King Henry Eight,is known for bringing down the house. At one of the first performances in 1613, a special effects cannon shot set the straw roof of the Globe Theatre on fire, and the venue burned to the ground.

Similar artificial intelligence programs have been applied to music and painting, not only to determine authorship but to make new works in the style of known authors. New pieces inspired by 19th century Czech composer Antonín Dvořák, made with an artificial intelligence program, were recently performed in Prague.