In addition to the thirty-six plays of the First Folio, some eighty plays have been attributed in whole or part to William Shakespeare, yet most are rarely read, performed or discussed. This book, the first to confront the implications of the 'Shakespeare Apocrypha', asks how and why these plays have historically been excluded from the canon. Innovatively combining approaches from book history, theatre history, attribution studies and canon theory, Peter Kirwan unveils the historical assumptions and principles that shaped the construction of the Shakespeare canon. Case studies treat plays such as Sir Thomas More, Edward III, Arden of Faversham, Mucedorus, Double Falsehood and A Yorkshire Tragedy, showing how the plays' contested 'Shakespearean' status has shaped their fortunes. Kirwan's book rethinks the impact of authorial canons on the treatment of anonymous and disputed plays.