Thomas Kyd's The Spanish Tragedyis an outstanding landmark of Elizabethan tragedy. In its time, it quickly became a box office success, with frequent revivals, and one of the most frequently printed plays. It probably inspired Shakespeare to write Hamlet, as it contains a ghost, murders that demand revenge and a hero that hesitates and contemplates suicide. As a revenge tragedy, it set up the salient features of a dramatic genre that would last decades. Its hero, the aged Marshall of Spain Hieronimo, whose son is murdered at night, soon transcended the play and became the standard stage representation of grief, rhetorical passion and madness. Hieronimo's main antagonist is one of the first Machiavellian characters of English drama. The play has a resonant finale, in which Hieronimo is aided by a resolute and defiant heroine, Bel-imperia. A convoluted plot, an intriguing murder and the delay in the action make this play a forerunner of the detective genre. This edition explores the play in relation to its historical context and contemporary Iberian dynastic policy. It also relates the play, as a literary artefact, to other artistic manifestations of the European Renaissance and offers a fresh assessment of the play's stage history. For the first time in the play's textual history, this edition presents an integrated text inviting a reading of the play as it was published both in 1592 and in 1602.