(dĕl'fī), locality in Phocis, Greece, near the foot of the south slope of Mt. Parnassós, c.6 mi (10 km) northeast of the port of Cirrha. It was the seat of the Delphic oracle, the most famous and most powerful of ancient Greece. The oracle originated in the worship of an earth-goddess, and later legend ascribed it to Gaea. It passed to Apollo; some stories say he won it by killing the Python, others that it descended to him peacefully through Themis and Phoebe. The Delphic oracle was the preeminent shrine of Apollo, but in winter, when Apollo was absent among the Hyperboreans, it was sacred to Dionysus, who was said to be buried there.
The oracle was housed in the great temple to Apollo, first built in the 6th cent. B.C. (it was destroyed and rebuilt at least twice). The oracular messages were spoken by a priestess seated on a golden tripod, who uttered sounds in a frenzied trance. The inspired trance was said by the ancient Greeks to be induced by vapors from beneath the temple's floor; these may have been ethylene or other petrochemical fumes rising through faults that ran beneath the temple. The priestess's utterances were interpreted to the questioner by a priest, who usually spoke in verse.
Delphi was unique in its universal position in the otherwise fragmented political and social life of Greece. It was the meeting place of the Amphictyonic league (see amphictyony), the most important league of Greek city-states, and also the site of the Pythian games. Persons seeking the help of the oracle brought rich gifts, and the shrine grew very wealthy. The prestige and influence of the Delphic oracle prevailed for centuries through all of Greece. During Hellenistic times, however, the importance of the oracle declined. Delphi was frequently pillaged from early Roman times, and the sanctuary fell into decay. One of the art works excavated there is the beautiful 5th-century bronze statue called the Delphic Charioteer (now at the Archaeological Mus., Delphi, Greece).