Python. In Greek mythology, Python was the serpent, sometimes represented as a medieval-style dragon, living at the center of the earth, believed by the ancient Greeks to be at Delphi. Python, sometimes written Phython, presided at the Delphic oracle, which existed in the cult center for its mother, Gaia, Earth, Pytho being the place name that was substituted for the earlier Krisa. Greeks considered the site to be the center of the earth, represented by a stone, the omphalos or navel, which Python guarded. Python became the chthonic enemy of the later Olympian deity Apollo, who slew it and took over Python's former home and oracle. These were the most famous and revered in the ancient Greek and Roman worlds. There are various versions of Python's birth and death at the hands of Apollo. In the Homeric Hymn to Apollo, now thought to have been composed in 522 BCE when the archaic period in Greek history was giving way to the Classical period, a small detail is provided regarding Apollo's combat with the serpent, in some sections identified as the deadly drakaina, or her parent. The version related by Hyginus holds that when Zeus lay with the goddess Leto, and she became pregnant with Artemis and Apollo, Hera was jealous and sent Python to pursue Leto throughout the lands, to prevent her from giving birth to the twin gods. Thus when Apollo was grown he wanted to avenge his mother's plight and pursued Python, making his way straight for Mount Parnassus where the serpent dwelled, and chased it to the oracle of Gaia at Delphi; there he dared to penetrate the sacred precinct and kill it with his arrows beside the rock cleft where the priestess sat on her tripod. Robert Graves, who habitually read into primitive myths a retelling of archaic political and social turmoil, saw in this the capturing by Hellenes of a pre-Hellenic shrine. To placate local opinion at Delphi, he wrote in The Greek Myths, regular funeral games were instituted in honour of the dead hero Python, and her priestess was retained in office. The politics are conjectural, but the myth reports that Zeus ordered Apollo to purify himself for the sacrilege and instituted the Pythian Games, over which Apollo was to preside, as penance for his act. Erwin Rohde wrote that the Python was an earth spirit, who was conquered by Apollo, and buried under the Omphalos, and that it is a case of one god setting up his temple on the grave of another. The priestess of the oracle at Delphi became known as the Pythia, after the place-name Pytho, which Greeks explained as named after the rotting of the slain serpent's corpse in the strength of Hyperion or Helios. Karl Kerenyi pointed out that the older tales mentioned two dragons, who were perhaps intentionally conflated; the other was a female dragon named Delphyne in the Homeric Hymn to Apollo, with whom dwelt a male serpent named Typhon: The narrators seem to have confused the dragon of Delphi, Python, with Typhon or Typhoeus, the adversary of Zeus. The enemy dragoness. actually became an Apollonian serpent, and Pythia, the priestess who gave oracles at Delphi, was named after him. Many pictures show the serpent Python living in amity with Apollo and guarding the Omphalos, the sacred navel stone and midpoint of the earth, which stood in Apollo's temple. This myth has been described as an allegory for the dispersal of the fogs and clouds of vapor which arise from ponds and marshes by the rays of the sun.