At Dodona (modern Dodoni) in Epirus, northwestern Greece, was a prehistoric oracle devoted to the Greek god, Zeus and the "Mother Goddess" identified at other sites with Rhea or Gaia, but here called Dione. The shrine of Dodona was the oldest Hellenic oracle, according to the fifth-century historian Herodotus and in fact dates to pre-Hellenic times, perhaps as early as the second millennium BCE. Priests and priestesses in the sacred grove interpreted the rustling of the oak (or beech) leaves to determine the future.
At Dodona Zeus joined a pre-Greek name to his own and was worshipped there as "Zeus Molossos" or as "Zeus Naios." Originally, the oracle was that of both Zeus and the Earth Mother. Many dedicatory inscriptions recovered from the site mention both "Zeus Naios" and "Dione." Elsewhere in Classical Greece, Dione (the nameless consort "goddess") was relegated by Classical times to a minor role, an aspect of Zeus's more usual consort, Hera.
When Homer wrote the Iliad (circa 750 BCE), no buildings were present and the priests slept on the ground with ritually unwashed feet. Not until the fourth century BCE, was a small stone temple to Zeus added to the site. By the time Euripides mentioned Dodona (fragmentary play Melanippe), and Herodotus wrote about the oracle, priestesses called peleiades had largely replaced the male priests. Though it never eclipsed the Oracle of Apollo at Delphi, Dodona gained a reputation far beyond Greece. In Apollonius of Rhodes' Argonautica, a retelling of an older story of Jason and the Argonauts, Jason's ship the Argos had the gift of prophecy, because it contained an oak timber spirited from Dodona.
In the third century BCE, King Pyrrhus, grandly rebuilt the Temple of Zeus, added many other buildings and a festival featuring athletic games, musical contests and drama enacted in a theatre. A wall was built around the oracle itself and the holy tree, as well as temples to Heracles and Dione.
In 219 BCE, the Aetolians invaded and burned the temple to the ground. Though King Philip V of Macedon rebuilt all the buildings bigger and better than before, and added a stadium for annual games, the oracle at Dodona never fully recovered. In 167 BCE, Dodona was once again destroyed and later rebuilt 31 BCE by Emperor Augustus. By the time the traveller Pausanias visited Dodona in the second century AD, the sacred grove had been reduced to a single oak (Description of Greece, I, xviii). Pilgrims still consulteded the oracle until CE 391, when Christians cut down the holy tree. Though the surviving town was insignificant, the long-hallowed pagan site must have retained significance, for a Christian Bishop of Dodona attended the Council of Ephesus in CE 431.
Archaeological excavations over more than a century have recovered artefacts, many now at the National Archaeological Museum, Athens, and some in the archaeological museum at nearby Ioannina.