Mythological versions of the foundation of the Oracle

Ancient authors relate the following variations of the foundation myth of the sanctuary and oracle of Delphi:

Diodorus' "scientific" version
Diodorus of Sicily (XVI, 26, 1-6) speaks of a shepherd who, while grazing his flock in the area, noticed fumes being emitted from a gap next to the Phaedriades. In fact, he observed that the animals, upon approaching this gap, began to behave in a very strange way. As he approached the cavity he began to utter incomprehensible words and fell into a trance. Subsequently, it became evident that these words predicted the future. From then onwards, the Pythia, a priestess, settled there and founded the Oracle.

The Homeric version

According to the Homeric “Hymn to Apollo”, the god had a hard time discovering a suitable place to establish his oracle. He started from Mt. Olympus and after crossing Lektos and the areas where the Aenians and the Perrhaevians used to live, he arrived at Iolkos. From there, he crossed to Euboea, to the cape of Kinaio, stopped at the Lelantine plain and from Euripus he returned again to Mainland Greece. Leaving behind Mt. Messapio, he passed through Mykalessos and Teumessos and then reached Thebes. Not even Thebes satisfied him, so he headed towards Onchestos, crossed the Kephissus river and after passing Okaleia and Aliartos, he reached the waters of the Telphoussian spring at the feet of the homonymous mountain. The nymph Telphousa persuaded him to move on towards Krisa. 

Hence, leaving Panopeus behind, the town of the presumptuous Phlegyans in Kopais, Apollo arrived in Krisa to establish the Oracle on the slopes of Mt. Parnassus. However, he realized that he had been deceived by the nymph Telphoussa who had directed him to an uninhabited rocky location.  For this reason, he returned to Telphoussa spring, buried the water beneath a pile of stones, and then built his own altar right next to it. After that, using an arrow, he killed a a female dragon who fed on humans and animals and, as she lay dying, Apollo shouted at her: "above the earth and under the blaze of the sun rot, not to hurt the people who will come to offer me sacrifices and to request from  me an oracle”.

According to the Hymn, the first priests of the Oracle were Cretans who were saved by the god who had taken the shape of a dolphin and carried them on his back safely to the shore. When they asked the god how they would manage to live in this place he god replied that they would live off the offerings of the pious flock.  Thus, the Cretans instigated the worship of Apollo Delphinios and the place was named Delphi.