a Latin heroic poem of the 9th or 10th century dealing with Germanic hero legend. Its author was once thought to be the Swiss monk Ekkehard I the Elder (d. 973), but research since 1941 has determined that the author was probably a Bavarian, one Geraldus, or Gerald, who was certainly the author of the metrical prologue.

The action of the 1,456-line poem is set in the time of the migrations of the peoples. Threatened by the Huns under Attila, the kings of the Franks, of the Burgundians, and of Aquitaine decide to pay tribute and give hostages: Gibicho gives his noble follower Hagano; Heriricus, his daughter Hiltgunt; and Alphere, his son Waltharius—i.e., Walter of Aquitaine. The three children are educated by the Huns in a manner suited to their station.

Hagano escapes when it is learned that Gibicho has died and his son Guntharius does not intend to continue the tribute. In order to bind Waltharius to him, Attila proposes that he should marry a princess of the Hun realm; but he and Hiltgunt have been betrothed as children, and they plan an escape. Their presence in his realm is revealed to Guntharius as they cross the Rhine River. Hagano recognizes from their description who they are, but Guntharius insists on pursuing them to take their treasure. The rest, and by far the larger part, of the poem is devoted to his attempts to do so.

When Waltharius sees the danger, he takes up his position in a narrow ravine in the Vosges, where only one adversary can approach at a time, and there follows a series of single combats (skillfully varied by the poet) of Waltharius with the 11 warriors of Guntharius, all of whom Waltharius kills. After resting for the night, he and Hiltgunt continue their journey and are attacked in open country by Guntharius and Hagano, who has hitherto refrained from taking arms against his friend but is finally persuaded by his master that his duty to him now requires it. Guntharius, Hagano, and Waltharius are all seriously wounded, but none is killed; and Waltharius and Hiltgunt continue on their way.

The story became well known in Germany, and there is an account, albeit with considerable differences, in the Norse Thidriks saga. Two short fragments of Waldere in Anglo-Saxon alliterative verse are clearly related, in spite of differences; they are not believed to predate Waltharius. It is possible that both Waldere and Waltharius are derived from a lost Germanic heroic lay; three of the principal characters, Attila, Gunther, and Hagen, are known from other poems of the heroic age. However, the part of the poem containing the single combats draws heavily on Latin literature.