The Pythia (/ˈpɪθiə/,Ancient Greek: Πῡθίᾱ [pyːˈtʰi.aː]), commonly known as the Oracle of Delphi, was the name given to the High Priestess of the Temple of Apollo at Delphi who also served as the oracle.
The name Pythia is derived from Pytho, which in myth was the original name of Delphi. In etymology the Greeks derived this place name from the verb, πύθειν (púthein) "to rot", which refers to the sickly sweet smell of the decomposition of the body of the monstrous Python after he was slain by Apollo. Pythia was the House of Snakes.
The Pythia was established in the 8th century BC, and was widely credited for her prophecies inspired by being filled by the spirit of the god (or enthusiasmos), in this case Apollo. The Pythian priestess emerged pre-eminent by the end of 7th century BC and would continue to be consulted until the 4th century AD. During this period the Delphic Oracle was the most prestigious and authoritative oracle among the Greeks, and she was without doubt the most powerful woman of the classical world. The oracle is one of the best-documented religious institutions of the classical Greeks. Authors who mention the oracle include Aeschylus, Aristotle, Clement of Alexandria, Diodorus, Diogenes, Euripides, Herodotus, Julian, Justin, Livy, Lucan, Nepos, Ovid, Pausanias, Pindar, Plato, Plutarch, Sophocles, Strabo, Thucydides and Xenophon.