DIIPOLIE (Διπύλια). - A festival of the Athenian calendar falling on the 13th day of the month Skirophorion (= 29 June). It was dedicated to Zeus Policus, protector of the city, whence its name, and was also called βουφένια because the sacrifice consisted in the ritual killing of an ox, a rite attested by Porphyry, De abst., 11, 29, by Aelian, Var. Hist., VIII, 3, and by the scholiast on Aristophanes, Nubes, 984.
The ceremony took place in two stages. In the first, oxen were led onto the acropolis before the open-air altar of Zeus, upon which a cake of wheat and barley had been placed, in which the spirit of the harvest was concentrated. The ox that first tasted it was killed with an axe by a priest, who then threw the axe away and fled. The axe was tried in the Prytaneum as guilty of sacrilege and cast into the sea. In the second stage, the ox was flayed, its skin stuffed with straw and yoked to the plough; the meat was distributed among those present.
This was an agrarian sacrifice, performed at harvest time. The first fruits offered to Zeus were sacred, and therefore the ox was punished with death; but the axe that had killed an animal made sacred because it had consumed a sacred thing was also punished. This, representing the vegetative spirit of the harvest, possessed a fertilizing power expressed by the yoking to the plough of the straw-stuffed ox, that is, resurrected insofar as it had incorporated the spirit of vegetation.