One would expect two folk tales classified as the same type according to the Aarne-Thompson (AT) classification system would be very similar. This is not always the case. For example, both "The Three Sisters", a folk tale collected by the Grimm's, and the Greek tale "The Navel of the Earth" are classified as AT 552, but the plot of each of these tales is distinct. In fact, the two tales only have one motif in common, while all other motifs are unique to each particular tale. Although their is only one motif in common, the events of the tale are still similar enough to be comparable.
In both tales, as in the majority of folk tales, the king is involved in the marriage of his daughters. In "The Three Sisters", the bankrupt king promises each daughter individually to animals in exchange for his life and a small treasure [S221.1]. The daughters wed these animals [B640] that spared their father's life. These same animals turn out to be enchanted princes who regularly transform back into their human form [D620]. Slightly different events occur in "The Navel of the Earth". In this tale, the dying king requests his sons' promise that they will allow the first suitors that arrive to marry their sisters. The princesses in "The Navel of the Earth" wed beast-like, deformed men (drakoe) [T268], not animals.
After the initial situation, the events in each story diverge considerably. In "The Three Sisters", the king and queen, after mourning the loss of their three daughters, give birth to a prince. When he reaches a mature age, the prince goes out in search of his sisters. The youngest prince also goes on a quest in "The Navel of the Earth", but for dissimilar reasons. He is in search of the Beauty of the World, and only by chance does he come upon his sisters.
The prince of "The Three Sisters" finds his sisters, each separately, and they hide him until their husbands transform into men. When the princes emerge from their beastly bodies, they invite their brother-in-law into their home. They warn him, however, that he must leave before they become animals again, and he accepts this. Similar events occur in "The Navel of the Earth". When the prince arrives at the kingdom of the Beauty of the World, her father, the king, poses a task on the boy. He must go underground for forty days and contemplate the contents of the navel of the earth. If the prince answers correctly, the Beauty of the World may be his bride [T151.0.1] While underground, the prince finds a window to another world and enters it. It is in this world that the youth finds his sisters, each individually, as in "The Three Sisters". Also as in "The Three Sisters", he is forced to be hidden by each sister until they are sure their brother can surface without being hammed by their husbands. His safety is assured, and the prince is greeted warmly by each of his three brothers-in-law in tum.
In both folk tales, the prince receives some kind of assistance from his brothers-in-law [B314]. The help is different in each story, though. In "The Three Sisters", before the young lad departs from his sisters' homes, he receives a magical gift from each of his brothers-in-law [B505.1]: three hairs from the bear, three feathers from the eagle, and three scales from the whale [B501]. In "The Navel of the Earth", on the other hand, they help him discover what is in the navel of the earth, and thus, win his bride, the Beauty of the World [B599.2].
"The Three Sisters" and "The Navel of the Earth" are the same tale type, AT 552. Despite this, the plots have such different details, that they only have one motif in common: B314, helpful animal brothers-in-law. Altough they are so different in motifs. The two tales still have similar plots. This lends them easily to comparison.
Written by Twila Wingrove