SINOICHIA (Συνολια). — Athenian festival celebrated on the 16th of Hecatombaeon (July–August) in honor of Athena, protector of the State, to commemorate the peace and reunion among the ancient cities restored by Theseus.
In this festival, which constituted a kind of prelude to the Panathenaea, an unbloody sacrifice was offered to Peace, as far as can be determined, probably in the ancient Prytaneum, before the statue of Eirene; in a later period (4th century B.C.), however, the sacrifice was offered with numerous animal victims.
BIBL.: L. Deubner, Attische Feste, Berlino 1932, pp. 36–38. Cesare D'Onofrio