What is "hildebrandslied"

The Hildebrandslied (lay or song of Hildebrand) is a heroic epic poem written in Old High German alliterative verse. It is one of the earliest literary works in German, and it tells of the tragic encounter in battle between a son and his unrecognized father. It is the only surviving example in German of a genre which must have been important in the oral literature of the Germanic tribes.