This essay introduces The Ireland Prophecy, a late fifteenth-century English alliterative poem extant in six manuscripts. The poem survives in three textual versions of different lengths, indicating rolling revision by many hands over a decade or more. It belongs to two written traditions: British political prophecy as in Geoffrey of Monmouth’s Prophetie Merlini, and English alliterative verse. This essay discusses the manuscripts and textual history of The Ireland Prophecy, offers a first critical text, analyzes the poem’s meter in light of recent progress in Middle English alliterative metrics, and positions the poem as a case study in the cultural meaning of alliterative verse after 1450. The essay proposes to show how meter, literary history, and literary culture intersect and illuminate one another in and through a particular poetic composition.