A historical nucleus of the saga lies in events of the Germanic Migration Period, in particular the defeat of the Burgundians by Flavius Aëtius with the aid of Hunnic mercenaries near Worms in ca. AD 436. Other possible influences are the feud between the 6th century Merovingian queens Brunhilda and Fredegunde, as well as the marriage of Attila with the Burgundian princess Ildikó in AD 453, the very last of his wives just before he died, the day after the marriage.
From the evidence of Waltharius, Nibelung is a part of the name for Franks, although there are other uses of the name in other medieval texts. The Nibelungenlied combines a first part dealing with Gunther's wooing of Brünhild and the Murder of Siegfried which takes place in Worms, with a second part, describing the journey of the Nibelungs east across the Danube to Etzelburg, the residence of Attila the Hun (Etzel), the location of the final catastrophe. The Nibelungenlied arranges these traditional materials in a composition aiming at a High Medieval audience casting the inherited Germanic theme in a critical view of contemporary chivalry. Consequently, Siegfried changes from a dragon killer to a courtly man who will express his love to Kriemhild explicitly only after he has won the friendship of the Burgundian king Gunther and his brothers, Gernot and Giselher. Some situations, which exaggerate the conflict between the Germanic migrations and the chivalrous ethics (such as Gunther's embarrassing wedding night with Brünhild) may be interpreted as irony. The notoriously bloody end that leaves no hope for reconciliation is far removed from the happy ending of typical courtly epics, but is probably part of the original story. The bloody conclusion is also part of the overall critical dimension of the work.
Some scholars, particularly Delbrück, consider the historical figure of Arminius (Hermann), who defeated the Roman imperial legions (clad in scale armour) at the Battle of Teutoburg Forest in 9 AD, a possible archetype for the dragon-slayer Siegfried.