On trial for heresy in sixteenth-century Venice, Isabella della Frattina reproached the Inquisition tribunal for daring to judge the true nature of her faith based on evidence provided by others. Only God and her conscience, the noblewoman declared, could truly know her beliefs. Isabella’s declaration applies just as well to the modern historian trying to piece together her beliefs at a distance of centuries based on fragmentary, ambiguous evidence. Federica Ambrosini’s well-executed edition of Isabella’s trial neatly illustrates the possibilities and limits of the evidence available to us in such cases.

Isabella was born in Padua, descended from Genoese aristocracy, and married into the Friulian nobility — a set of overlapping identities that Ambrosini suggests explains how she came to be tried by the Holy Office and why her trial unfolded as it did. Della Frattina was denounced in a somewhat tentative fashion by her own mother, undergoing a heresy trial in Mantua. Isabella’s case was soon taken up by the Holy Office of Venice, which confined her to the posh convent of S. Zaccaria while the tribunal investigated and Isabella, with her husband and her lawyer, mounted her defense. Just shy of two years after confining her to S. Zaccaria, the Inquisition declined to convict Isabella and ordered her release.

Ambrosini’s presentation of Isabella’s trial dossier strikes a pleasant editorial balance between enhancing the documents’ readability and retaining their original character. The apparatus is solid if not extensive. Most of the footnotes identify the many individuals referenced in the proceedings and reveal a prodigious amount of archival and library research. Ambrosini also explains points of inquisitorial procedure and some of the religious issues implicated in the trial. Specialists will be satisfied with what she provides, but readers less familiar with the context might wish for more. The same might be said about Ambrosini’s introduction. Whereas the trial documents run to nearly 400 pages, the introduction is somewhat terse, not quite reaching seventy pages. Readers seeking a more expansive version of Ambrosini’s insights should turn to her earlier publications based on these materials, especially L’eresia di Isabella: Vita di Isabella da Passano, signora della Frattina (2005).

In her analysis here, Ambrosini delves into the nature of religious dissent in Venice and Northern Italy, exploring the political dimension of Venice’s policies on religion and the character of communities of dissenters. She also highlights the fascinating glimpses of life in an aristocratic household that the trial provides. Ambrosini’s introduction notes some peculiarities of Isabella’s trial as well, such as that the noblewoman remained the Inquisitors’ sole focus in a context that usually saw men as the central figures in heresy trials. The Holy Office showed remarkably little interest in pursuing Isabella’s husband — or, indeed, anyone else in the community. Ambrosini suggests that this was a deliberate choice by the political and religious authorities of Venice. As something of an outsider, Isabella could be prosecuted as a warning to the other nobility of the Terraferma flirting with heterodoxy, without overly agitating that same, restive nobility.

In her introduction, Ambrosini is not averse to speculating about historical actors’ motives and beliefs. She casts Isabella, for example, as a woman of unusual intellectual sophistication who felt stifled by a religious tradition that had decayed into “mere formal observance [and] mechanical performance” of minor acts (xlviii). Consequently, early in her marriage the self-confident Isabella and her husband began to explore other religious paths. Ambrosini declines, however, to take a position on whether at the time of her trial Isabella had reverted to an orthodox Catholicism or was a particularly clever Nicodemite. That question remained unsettled in the trial itself, as the inquisitorial tribunal split two to one in their vote to release Isabella.

Ambrosini might have explored other significant aspects of the trial, such as the issue of women’s curiosità, but that more remains to be said about this trial is a reminder of why books like this one are valuable. A high-quality edition, informed by deep background knowledge, encourages further work heading in different directions. This book is just such a resource.