This dissertation studies a local manifestation of ecclesiastical reform in the medieval county of Savoy: the twelfth-century transformation of secular canons into Augustinian regular canons at the church of Sts. Peter and Ursus in the alpine town of Aosta (now Italy). I argue that textual sources, material culture, and the practice of place together express how the newly reformed canons established their identity, shaped their material environment, and managed their relationship with the unreformed secular canons at the cathedral. The pattern of regularization in Aosta—instigated by a new bishop influenced by ideas of canonical reform—is only one among several models for implementing reform in medieval Savoy. This study asserts the importance of this medieval county as a center for reforming efforts among a regional network of churchmen, laymen, and noblemen, including the count of Savoy, Amadeus III (d. 1148). After a prologue and introduction, chapter 1 draws on traditional textual evidence to recount the history of reform in medieval Savoy. Chapters 2 through 4 focus on the twelfth-century sculpted capitals in the cloister built to accommodate the common life of the new regular canons. Several of the historiated capitals portray the biblical siblings, Martha and Mary, and Leah and Rachel, as material metaphors that reflect and reinforce the active and contemplative lives of the Augustinian canons. Other capitals represent the regular canons’ assertion of their precedence over the cathedral canons and suggest tensions between the two communities. The final chapter examines thirteenth-century conflicts over bell-ringing and ecclesiastical processions in the urban topography of Aosta to illustrate how the regular and secular canons continued to negotiate their relationship. Appendices include an English translation of a vita of St. Ursus (BHL 8453). The dissertation as a whole reconstructs the places and material culture of medieval Aosta to convey the complexities of religious and institutional life during a time of reform and beyond. / text