This dissertation examines the intersection of spiritual values and material life at Syon Abbey, a wealthy Brigittine double monastery in late medieval England. As an institution it was, paradoxically, directed primarily toward an evangelical goal, while being focused on contemplative women who were strictly enclosed. In this dissertation, I assert that this apparent contradiction was resolved through a high degree of collaboration between the abbey’s religious women and men. I argue that Brigittine monasticism, and that of Syon in particular, was uniquely attuned to metaphors and meanings of materiality, which enabled the abbey to transform the women’s mundane material life of food, clothing, architecture, work, finance, and even bureaucracy, into spiritual fruits to be shared with the Syon brethren through dialogue within confessional relationships, and subsequently, with the laity through the media of sermons, sacraments, books, and conversation. I use the abbey’s extensive household financial accounts in conjunction with Brigittine writings and monastic legislative documents to examine the intersection of ideal material life and its spiritual meaning on the one hand, and the abbey’s lived materiality as reflected in its internal economic and administrative actions, on the other. The central question is the degree to which Syon’s material life was one of luxury in keeping with what the Order’s founder, Saint Birgitta, would have seen as worldly excess, or one of moderate asceticism, in keeping with the Brigittine Rule. Major findings are that in most respects (financial management, gender power, officer appointments, clothing, and some aspects of food), Syon’s materiality was lived in accordance with the Rule and the Brigittine mission, but that in some respects, it erred on the side of elite display and consumption (the majority of food items and the architecture and decoration of the abbey church), and in others, the source material is too incomplete to enable conclusions (the decoration of monastic buildings and the distribution of alms). In addition, by analysing the income from boarding of visitors and offerings from pilgrims, I examine the degree of Syon’s impact on the laity and how it changed with the approaching Dissolution, concluding that the abbey had a significant impact that declined only when legal restrictions were applied.