This paper investigates the political and religious implications of the baptisms of enslaved women in early modern Livorno, focusing on the conversions of Muslim and Jewish captives held in the slave prison. While Livorno has often been portrayed as a tolerant and cosmopolitan free port shaped by the Livornine, its daily reality was marked by the contradictions inherent in a city that functioned both as a space of interreligious coexistence and as a military stronghold engaged in Mediterranean corsairing warfare. Within this complex environment, enslaved populations—men, women, and children-—became deeply embedded in the city's social and institutional structures. The paper examines how baptism, administered from the late seventeenth century by the Capuchins of the Bagno and by the Hospital of Santa Barbara, operated as a key instrument of grand ducal religious and political policy. Unlike Florence, Livorno lacked a formal House of Cathecumens; baptisms were therefore performed directly inside the slave prison's chapel under the authority of the Archbishop of Pisa. The paper argues that female conversions held a distinctive political resonance. For enslaved women, whose opportunities for social or legal negotiations were extremely limited, baptism constituted one of the few available means of altering their condition, offering potential improvements in treatment or symbolic protection. For state authorities, these ceremonies functioned as performative affirmations of Christian power, particularly in the case of Jewish women, whose conversions carried heightened theological significance. Ultimately, the paper contends that the conversion of enslaved women was not a marginal phenomenon but a crucial mechanism of religious assimilation and the state's assertion of power within the broader political and confessional strategies of the Medici Grand Duchy