The Black Widows of the Eternal City offers, for the first time, a book-length study of an infamous cause célèbre in seventeenth-century Rome, how it resonated then and has continued to resonate: the 1659 investigation and prosecution of Gironima Spana and dozens of Roman widows, who shared a particularly effective poison to murder their husbands. This notorious case has been frequently discussed over 350 years, but the earliest writers concentrated more on fortifying their reading constituency’s shared attitudes than accurately narrating facts. Subsequent authors remained largely content to follow their predecessors or keen to improve upon them. Most recent writers and bloggers were unaware that their earlier sources were generally unconcerned with a correct portrayal of real events. In the present study, Craig A. Monson takes advantage of a recent discovery—the 1,450-page notary’s transcript of the 1659 investigation. It is supplemented here by many ancillary archival sources, unknown to all previous writers. Since the story of Gironima Spana and the would-be widows is partially about what people believed to be true, however, this investigation also juxtaposes some of the “alternative facts” from earlier, sensational accounts with what the notary’s transcript and other, more reliable archival documents reveal. Written in a style that avoids arcane idioms and specialist jargon, the book can potentially speak to students and general readers interested in seventeenth-century social history and gender issues. It rewrites the life story of Gironima Spana (largely unknown until now), who has dominated all earlier accounts, usually in caricatures that reiterate the tropes of witchcraft. It also concentrates on the dozen other widows whose stories could be the most recovered from archival sources and whom Spana had totally eclipsed in earlier accounts. Most were women “of a very ordinary sort” (prostitutes; beggars; wives of butchers, barbers, dyers, lineners, innkeepers), the kinds of women commonly lost to history. The book seeks to explain why some women were hanged (only six, in fact, most of whom may not have directly poisoned anyone), while dozens of others who did poison their husbands escaped the gallows and, in some cases, were not even interrogated. It also reveals what happened to these other alleged perpetrators, whose fates have remained unknown until now. Other purported culprits, about whom less complete pictures emerge, are briefly discussed in an appendix. The study incorporates illustrations of archival manuscripts to demonstrate the challenges of deciphering them and illustrates “scenes of the crime” and other important locations, identified on seventeenth-century, bird’s eye-perspective views of Rome and in modern photographs. It also includes GPS coordinates for any who might wish to revisit the sites.