Shakespeare's First Folio, published in 1623, is one of the world's most studied books, prompting speculation about everything from proof-reading practices in the early modern publishing industry to the 'true' authorship of Shakespeare's plays. Arguments about the nature of the First Folio are crucial to every modern edition of Shakespeare and thus to every reader or student of the plays. This Companion surveys the critical methods brought to bear on the Folio and equips readers with the tools to understand it and to develop their skills in early modern book culture more generally. A team of international scholars surveys the range of bibliographic, historical and textual material relating to the Folio, its editors, collectors and critical reception. This revealing volume will be of wide interest to scholars of Shakespeare, the history of the book and early modern drama.