The Carmen de bello Saxonico (German: Lied vom Sachsenkrieg; English: Song of the Saxon War) is an epic retelling in 757 hexameters in three books of the first phase of the Saxon Rebellion against the Emperor Henry IV, from its inception until the Battle of Spier in October 1075. It is also limited geographically to the Harz region. It is strongly imperialist in tone, and complements the pro-Saxon histories of Bruno the Saxon and Lambert of Hersfeld. It was first written within months of the events it describes. The only existing manuscript dates from the sixteenth century. It received its first critical edition from Georg Heinrich Pertz in 1851.
There is internal evidence that the anonymous author made use of Virgil, Horace, Lucan, Ovid, Sedulius, Venantius Fortunatus and the anonymous Poeta Saxo, and that he was familiar with the imperial court. Early students of the text proposed as its author Lampert of Hersfeld, but this suggestion was quickly dispelled. Today it is commonly thought that the same anonymous poet composed the Vita Heinrici IV imperatoris, a biography of Henry IV, some three decades after composing the Carmen. His familiarity with local geography hints that he may have been a royalist Saxon, like the Poeta Saxo of two centuries earlier.