This thesis examines the religious writings of three seventeenth-century English nuns, Gertrude More (1606-1633), Catherine Gascoigne (1601-1676) and Barbara Constable (1617-1684), from a feminist perspective on agency and mysticism. All three women lived at the Benedictine monastery of “Our Lady of Consolation” in Cambrai (now in France), exiled from Anglican England because of their Catholic faith. It is argued that the texts of More, Gascoigne and Constable show that their agency was expressed not against or in spite of their religion, but rather through it. On the one hand, they rejected blind obedience to dominant superiors, though without violating religious monastic rule. On the other hand, they developed their own spirituality and mysticism based on medieval and contemplative teachings. More, Constable and Gascoigne, each in their own way, had a close spiritual relationship with their male spiritual instructor, David Baker, whose religious name was Augustine (1575-1641). Baker was a Benedictine monk best known for his writings on mystical spiritual contemplation. He played an important role in the lives of the three nuns, both in their personal and spiritual development. This thesis examines the extent to which More, Constable and Gascoigne mixed their own spiritual perspectives with those of Baker and how this affected their 'agentic capacity'. The study shows that Baker and each of the three nuns influenced each other in a positive way, leading to their personal and spiritual empowerment.