Among those witnesses of John Gower's works that are known to have been produced during his lifetime, the Trentham manuscript (London, British Library, Additional MS 59495) stands out for its remarkable design as a seemingly planned trilingual collection. The manuscript, usually dated to the first year of Henry IV's reign, exclusively contains Gower's poetry—showcasing his virtuosity in English, French, and Latin. A number of its poems are either addressed to or invoke Henry, yet nothing is known about the history of this manuscript before the seventeenth century. As a result, scholarship on the Trentham manuscript (henceforth Trentham) tends to foreground the question whether this compilation was ever presented to Henry. I will adduce fresh evidence to establish the early provenance of Trentham and show that the manuscript remained in Southwark until the middle of the sixteenth century. Second, I will offer a new context for the composition of Trentham by reading the collection against the background of Anglo-French relations during the first months of Henry's rule. Finally, I will argue for Gower's personal involvement in and continued ownership of this manuscript.