Boedromion was the third month of the Attic calendar (September-October). It was dedicated to Boedromion Apollo, the god who rushes to help in times of danger. There are several interpretations of the name. Plutarch explained it as an attempt to honour the god for his contribution to the Athenians' victory over the Amazons on the seventh day of the month. Other ancient sources derive the name from Apollo's contribution to the struggle against the Eleusinians. During the reign of the Athenian king Erechtheus, war broke out between the Athenians and the Eleusinians. The fierce conflict caused many prominent casualties, including Erechtheus and Eumolpus. The latter reigned in Thrace when the Eleusinians asked him to help them. He came with a strong army of Thracians and moved against Athens. Apollo supposedly told Erechtheus that his only chance of victory depended on the sacrifice of one of his daughters. The god also urged the Athenians to rush into battle with a war cry (“Boe”) if they wanted to prevail. In the ensuing conflict, the king of Athens killed Eumolpus but provoked the wrath of Poseidon, Eumolpus's father, who destroyed Erechtheus in turn.

Fragment of marble monumental Greek inscription; a decree concerning the Eleusinian Mysteries, 220, sculpture, The British Museum © The Trustees of the British Museum

Boedromion was the month of the Greater Mysteries. It also included less famous religious festivals such as the Boedromia in honour of Apollo, the Genesia or Nekysia (a celebration in memory of deceased loved ones) and the Charisteria dedicated to Artemis for her assistance in the Athenian victory at Marathon in 490 BCE. Moreover, the month seems to have been particularly favourable for the Athenian army since the naval battle of Salamis also took place in Boedromion (the 20th day, when the Great Procession from Athens to Eleusis usually took place), as well as the battle of Plataea in 479 BCE (on the 3rd day of the month).