The decision of the House of Lords in R v R [1992] 1 AC 599 stands as a transformative moment in English criminal law. For over two centuries, the common law had accepted the proposition, attributed to Sir Matthew Hale in 1736, that a husband could not be guilty of raping his wife, on the fiction that marriage entailed irrevocable consent to sexual intercourse. This case analysis examines how that doctrine was ultimately dismantled by the House of Lords in 1991. The paper traces the factual background of the case and its progression through the Crown Court and the Court of Appeal before reaching the House of Lords. It identifies the principal legal issues: whether the marital rape immunity formed part of English law, whether it could be abolished through judicial development of the common law, and whether such abolition would amount to impermissible retrospective criminalisation. The competing arguments of the prosecution and the defence are analysed, particularly the constitutional objection that reform of this magnitude was a matter for Parliament rather than the judiciary. The analysis further examines the reasoning adopted by the House of Lords in declaring the immunity obsolete, distinguishing the ratio decidendi from obiter dicta. Finally, the paper evaluates the decision’s doctrinal and constitutional significance, including its subsequent affirmation by the European Court of Human Rights and its role in reinforcing the principles of consent, bodily autonomy, and equality before the criminal law.