This study has two primary purposes; to examine the evolution of the concepts and statutes of Tudor treason legislation as reactions to unprecedented political, religious and social changes, and to develop the relationship between this thesis of treason and the Renaissance stage. An analysis of a broad and relatively un-researched body of historical and legal material accounts for the conditions in which writing, particularly the personal letter, aroused anxiety and suspicion. It is argued that this political and religious tension inspired the inclusion of writing as treason in the 1534 treason act, a statute drawing upon the concept of imagining the king's death of the Great Statute of Treason of Edward III. The letter is identified as the primary document of proof of "imagination" or intent in Tudor judicial opinion. A close study of treason trials of the period, in which the generic significance is the use of letters as evidence of intent against the alleged traitors, presages a substantive and novel reading of the chosen plays of this study, which foregrounds the discernable political and cultural anxieties of these judicial events. Differing, both in substance and approach, from traditional analyses, the treatment of each play (and other primary texts) evaluates and locates dramatic representations of treacherous correspondence within Tudor concepts of treason, while incorporating gender theory and post-structural reassessments of spoken and written language. In resituating Renaissance plays in the debate on treason, this study addresses the regulation of language, not merely within the Tudor law of treason by words, but also the play text, both complex, and, yet, mutable expressions of containment. It is, perhaps, the deliberate ambiguity of both statute and stage that allows continuing critique, such as that undertaken here.