The oldest known telling of the story comes from the 13th-century work attributed to Bishop of Kraków and historian of Poland,
Wincenty Kadłubek.
Polish Chronicle (13th c.) According to Wincenty Kadłubek's
Polish Chronicle, a dragon appeared during the reign of
King Krak (, "one who swallows whole"), which was a
neologism he had coined. In Polish translation of the work, the monster is rendered as the "greedily swallowing dragon" (). It was a "terrible and cruel beast" dwelling "in the depths [windings/curves] of a certain rock ('''')" or emended to "a certain cave ()" according to Wincenty. The dragon required a weekly offering of cattle, or else humans would have been devoured instead. In the hope of killing the dragon, Krak called upon his two sons. They could not, however, defeat the creature by hand, so they came up with a trick. They fed him a
cattle skin stuffed with smoldering sulfur, causing his fiery death. i.e.
Krak II; ) kills his elder brother blaming the dragon for the death. But his crime was soon revealed, and he got expelled from the country. Afterwards
Princess Wanda had to accede to the kingship.
Derivative chronicles Among later chronicles derived from Wincenty Kadłubek's work,
Chronicle of Greater Poland (<1296) fails to make mention of the dragon at all, while the (or
Mierzwa Chronicle;
Kronika Dzierzwy/
Kronika Mierzwy, 14th century) followed closely after Wincenty. Both these chronicles maintain that Krak, Jr. is the younger prince, and keep the elder brother nameless.
Jan Długosz's 15th-century chronicle, however, swapped the roles of the princes, claiming that the younger son named
Lech was the killer, while the elder son named Krak, Jr. became the victim. The idea for the scheme to slay the dragon (
olophagus) is credited to King Krak himself, not his sons, because the king fears a mass exodus from the city may take place, and he orders to have the carcass stuffed with flammable substances, namely sulfur,
tinder (; ), wax, pitch, and tar and set them on fire. The dragon ate the burning meal and died breathing fire just before death. Długosz also adds the detail that the dragon lived in a cave of Mount Wawel upon which King Krak had built his castle. In any case, the fratricide is banished, so their sister
Princess Wanda must accede to the throne. == Shoemaker version ==