The Jesuit mission to the South Indian city of Madurai, established in 1606 and suppressed in the mid-eighteenth century, was defined by an emphasis on philology and textual practices, and by an extraordinary literary production in Tamil. My project investigates the reasons and implications of this emphasis, and dwells especially on two questions: How did textual practices contribute to creating a space for Catholicism within South Indian society? And how did South Indian society, and especially its literary and religious institutions, shape the way Catholic missionaries wrote for that society? I address these questions by examining the life and intellectual trajectory of three Italian missionaries and authors in Tamil: Michele Bertoldi (1662-1748), Costanzo Giuseppe Beschi (1680-1742), and Giacomo Tommaso de Rossi (1701-1774). Bertoldi, Beschi and de Rossi worked in different areas of the mission — the village of Avoor, the village of Elakuricci, and the Maravar country, respectively. Adopting a micro-historical approach, and relying upon the texts these missionaries wrote along with contemporary sources in Tamil, Italian, Latin, French, Portuguese, and Sanskrit, my project investigates the networks of people and institutions with which they engaged in their respective locales, and the textual forms that were the outcome of this engagement, in the light of their Italian education, their intellectual training in South India, and the interaction between the two. These case studies reveal how the Madurai mission and its attendant literary practices became a site of encounter between certain forms of Jesuit and Italian humanist culture and specific aspects of early modern Tamil literary and religious ecology. My research offers an uncommon perspective on both these worlds, their mutual intelligibility and their idiosyncrasies, by focusing the ways in which they entered into communication with one another in early modern South India.