DELIA, in Antiquity, a festival celebrated every fifth year in the island of Delos, in honour of Apollo. It was first instituted by Theseus, who on his return from Crete placed at Delos a statue which he had received from Ariadne. At the celebration they crowned the statue of the god with garlands, appointed a choir of music, and exhibited horse-races. They afterwards led a dance, in which they imitated by their motions the various windings of the Cretan labyrinth, from which Theseus had extricated himself with Ariadne's assistance. There was another festival of the same name yearly celebrated by the Athenians at Delos, and also instituted by Theseus, who, when going to Crete, made a vow that if he returned victorious, he would yearly visit in a solemn manner the temple of Delos. The persons employed in this annual procession were called Delia and Theori; and the ship which had carried Theseus, and had been carefully preserved by the Athenians, was called Theoria and Delias. During this festival it was unlawful to put any one to death; and hence it was that the life of Socrates was prolonged for thirty days.