Summary How did medieval authors publish their works in the age before print? This study seeks to achieve new insights into the publishing strategies of medieval authors by focusing on Nicholas Trevet, an English Dominican friar and Oxford master. Shortly after 1317, Trevet was commissioned by his provincial prior to write a literal commentary on the Psalter. He chose as his reference version the less commonly used Latin translation by Jerome from the Hebrew, and delivered his work before 1321/22. The first book-length examination of Trevet's commentary, this detailed study traces the ways in which the work was circulated by the author and his proxies. Through a combined analysis of codicological, textual, and historical features of the nine extant fourteenth-century manuscripts, this study identifies contemporary efforts to make Trevet's work available to readers within and without the Dominican Order, in England and on the Continent. Even during the author's lifetime the commentary was copied in Paris and reached readers in Avignon and likely in Naples. TABLE OF CONTENTS Introduction Chapter 1. From Commission to Presentation: The Dedicatory Letter of the Expositio super Psalterium Chapter 2. The Publication of the Expositio in Light of the Earliest Manuscript Tradition: Codices MANCGHBR Chapter 3. The Publication of the Expositio in Light of the Earliest Manuscript Tradition: Codex extravagans (O) Chapter 4. The Effects of Publication: The Earliest Reception Chapter 5. The Effects of Publication: Fame Conclusions Appendices A. Psalm Numbering B. Descriptions of the Early Manuscripts C. Edition of the Dedicatory Letter D. List of Selected Variant Readings from the Collated Portions of the Expositio E. Register of Explicit References to Trevet's Expositio in the Commentary on the Psalms by Henry Cossey in Cambridge, Christ's College, MS 11 F. Illustration of Ps. 150 G. What Did Thomas Gascoigne See at a London Stationer's? H. Entries in Medieval and Early-Modern Documents That Refer to Trevet's Expositio, Other Than Those Identified with Extant Copies Bibliography Indices