Henry VI is a series of three history plays by William Shakespeare, set during the lifetime of King Henry VI of England. Henry VI, Part 1 deals with the loss of England's French territories and the political machinations leading up to the Wars of the Roses, as the English political system is torn apart by personal squabbles and petty jealousy; Henry VI, Part 2 depicts the King's inability to quell the bickering of his nobles, and the inevitability of armed conflict; and Henry VI, Part 3 deals with the horrors of that conflict.

Since the seventeenth century shakespeare editors and scholars have agreed, although not without dissent (eg from Alexander, who maintained that Henry VI, Part 1 was by Shakespeare alone), that the three Henry VI plays were the outcomes of collaborations between two or more playwrights, with Shakespeare's contributions being of varying scope and type. The nature of the collaborations is impossible to ascertain, and which parts may have been written by whom is also a matter of unresolved discussion. Careful analysis of the texts, of known practices of possible collaborators, and of the known performances of the plays, has resulted in some recurring names being suggested. For Henry VI, Part 1, the hands of Thomas Nashe, Christopher Marlowe, Greene and Peele have all been mentioned alongside that of Shakespeare, and there is some evidence to support some contributions from all of these, or any combination of these. John Dover Wilson's influential Preface to his 1952 edition of the play provides what remains, perhaps, the most thorough-going overview of all previous scholarship on the matter. His investigation leads him to suggest Nashe, Greene (with or without Peele) and Shakespeare as the coauthors and revisers of the play.^[1]

I. In 2016, scholars working on the New Oxford Shakespeare editions, and able to analyse the newly digitalised texts, found that 17 plays out of 44 showed Shakespeare as a collaborator; with regard to the Henry VI plays, they announced that they were crediting Shakespeare's colleague and sometime rival, Christopher Marlowe, as one of the co-authors of the trilogy.^[2]

II. The Oxford scholars drew their conclusions by using "big data" techniques, using computer software to identify signature language patterns for an author (using a discipline known as stylometrics), and then checking the texts against those signatures.

Although the Henry VI trilogy may not have been written in chronological order, the three plays are often grouped together with Richard III to form a tetralogy, the "minor tetralogy", covering the entire Wars of the Roses saga, from the death of Henry V in 1422 to the rise to power of Henry VII in 1485. It was the success of this sequence of plays which firmly established Shakespeare's reputation as a playwright. The "major tetralogy" or Henriad, covering the previous reigns, were written later.

The three plays were published separately, and have often been performed separately, although they have also been combined in various adaptations into a single play or two plays. Further details about performances and adaptations appear in the articles about the individual plays.