Because Gorboduc, or The Tragedie of Ferrex and Porrex (1561) sees a king divide his kingdom between his two sons while he still lives, much scholarship discusses the play as an Elizabeth succession parable. However, the printer John Day’s prefatory letter to his 1570 octavo (O2) provides a different frame, documenting an instance of Gorboduc’s later reception that scholarship has not yet recognized. This article argues that by comparing the playtext to a sexually assaulted woman Day does not merely advertise his edition’s supposed superiority to O1, as some have claimed. Considering Day’s reformist network, his investment in preserving Protestantism in England, and his output in 1570—including the massive second edition of Foxe’s Actes and Monuments and political treatises by Gorboduc’s co-author Thomas Norton—Day’s ‘better forme’ of Gorboduc becomes newly legible within histories of reading. For by claiming O2 will ‘play Lucreces part’, Day reads Gorboduc’s materialization of misrule’s effects through violence against ‘Mother Brittaine’ as anti-tyranny polemic—and asks book buyers to read it this way as well. Synthesizing historicist and feminist literary approaches with recent book historical work on paratexts, this article demonstrates how O2’s prefatory letter figures gender violence to justify resistance to tyranny.