An annual festival held at Agrae near Athens, in honour of Artemis Agrotera, in fulfilment of a vow made by the city, before the battle of Marathon, to offer in sacrifice a number of goats equal to that of the Persians slain in the conflict. The number being so great, it was decided to offer 500 goats yearly.
See Plutarch, De Malignitate Herodoti, 26; Xenophon, Anab. iii. 2.12; Aelian, Var. Hist. ii. 25; Schol. on Aristophanes, Equites, 660.