Pepin, king of the Franks, chooses Bertha, the daughter of a count, as his wife. The major-domo, charged with conducting the bride to the king, abandons her in the wilderness and substitutes his own daughter. Out hunting one day, Pepin comes across Bertha, who has been adopted by a miller. He recognises her, his lawful wife, by her feet, which are each of a different size. The king departs for war. When he returns many years later he finds that Bertha is a young mother. She presents him with their son, the future Emperor Charlemagne.
Bode separates the narrative into three parts. On the left, Bertha is watched over by an angel when threatened by a wolf in a dark forest. On the right, the king recognises the supposed miller’s daughter as Bertha while washing her feet. In the centre Pepin once more encounters Bertha, who is carrying the young Charlemagne in her arms. Bode based his treatment of the medieval legend on the version in the epic poem Bertha die Spinnerin (Bertha the Spinner, 1853) by the philologist and poet Karl Simrock.