The scenarios for both films were co-written by Lang's then-wife Thea von Harbou, based upon the epic poem Nibelungenlied written around AD 1200.

[1] Die Nibelungen received its UK premiere at the Royal Albert Hall in London, where it played for 40 performances between 29 April and 20 June 1924.

[2] Siegfried was released in the United States on 23 August 1925, premiering at the Century Theatre in New York City in the short-lived Phonofilm sound-on-film process.

The title character Siegfried, son of King Siegmund of Xanten, masters the art of forging a sword at the shop of Mime.

Mime, who is envious of Siegfried's skill as a swordsmith, claims there is a shortcut to Burgundy through the Wood of Woden, wherein dwell all kinds of dangerous creatures.

A fight breaks out between Siegfried and King Gunther and his adviser Hagen of Tronje, which is interrupted by the appearance of beautiful princess Kriemhild.

Hagen asks Siegfried to aid Kriemhild's brother, King Gunther, to win the hand of Brunhild, the Queen of Iceland.

In an evil twist of bitter revenge, Brunhild confesses that she lied about Siegfried stealing her maidenhood in order to avenge Gunther's deceit of her.

Kriemhild swears revenge against Hagen while Brunhild commits suicide at the foot of Siegfried's corpse, which has been laid in state in the cathedral.

Dietrich of Bern fetches the two remaining men from the palace and delivers them to Kriemhild, who demands Hagen to reveal the hiding place of the Nibelungen hoard.

When Hagen states that he has sworn not to reveal the hiding place as long as one of his kings is still alive, Kriemhild commands Gunther's beheading.

The early reception of the film was greatly impacted by its ideological and nationalist content, the German film critic Heinz-Udo Brachvogel wrote in a 1924 article: "Ancient, deepest popular sentiment poured into heavy verse, fiery, primitive passion, tamed by the gliding rhythm of poetic forms, the most human thing that endured through the storms of the centuries and had to endure because it was human in the highest potency".

[3] In 1928, Variety magazine published and article after Kriemhild's Revenge's premiere, claiming it was not a good film, and mentioned it had not been commercially successful.

[4] In 1947, film critic Lotte Eisner wrote an article titled On the style of Fritz Lang in the Révue du Cinema magazine.

In his review he wrote, "A rich treasure trove of folklore and magic, in which Lang creates a mystical geometric universe where the characters play against vast architectural landscapes.

Joseph Goebbels initially criticized the film in 1924 as a "typically Jewish concoction" although "the Jew knows how to direct", but later praised it as "the pinnacle of German achievement" by 1929.