Before Stephen Langton (DR 1228) was consecrated Archbishop of Canterbury, he was a prominent master of theology, belonging to the first generation of masters working in the Theology Faculty of the University of Paris. The Quaestiones Theologie constitute his chief theological work. The manuscript tradition of the Quaestiones originates in written reports (reportationes) of oral disputations held by Langton in Paris between c. 1180 and 1206. They reflect the development of Parisian educational practices and bring the contemporary reader very close to the first university lessons. The volume offers the first critical edition of Stephen Langton’s Quaestiones Theologiae, Book I, containing 23 Quaestiones on theological language, Trinity and God’s attributes. Each question is accompanied by a critical apparatus, extensive source notes and a separate philological introduction which explains the history of transmission and the main editorial problems of each text. The volume also contains a general introduction to the whole corpus of Langton’s Quaestiones, a presentation of philosophical and theological contents of Book I (including a chapter by E. Jennifer Ashworth) and an appendix, offering the first critical edition of a short fragment of Langton’s Summa.The edition offered in this book, and the philological analysis which precedes it, represent a significant contribution to the history of the early scholasticism, offering a ground-breaking study of an extremely complex work, which originates in oral teaching.