What was the name of Tolkien’s first major academic book on the Middle English poem Sir Gawain?

Tolkien’s major academic edition was titled Sir Gawain and the Green Knight. It was published in 1925 with E.V. Gordon, who was Tolkien’s colleague and collaborator.

The edition presented the Middle English poem with an introduction, notes, and glossary, helping make the difficult text accessible to students and scholars. Tolkien’s expertise included the language, literary traditions, and manuscript culture of medieval England.

Sir Gawain and the Green Knight tells of a supernatural challenger who proposes a beheading game at King Arthur’s court. Gawain accepts, then must face the consequences of the agreement a year later. Tolkien’s interest in the poem was scholarly rather than merely inspirational, although its combination of courage, testing, temptation, and moral complexity has clear appeal to readers of his fiction. The poem survives in a single medieval manuscript.