Iacchus

In Greek mythology, Iacchus (also Iacchos, Iakchos) (Ἴακχος) is an epithet of Dionysus, particularly associated with the Mysteries at Eleusis, where he was considered to be the son of Zeus and Demeter. Iacchus was the torch bearer of the procession from Eleusis, sometimes regarded as the herald of the 'divine child' of the Goddess, born in the underworld, and sometimes as the child itself. Iacchus was called "the light-bringing star of our nocturnal rite", giving him possible associations with Sirius and Sothis.

The most famous mention of Iacchus is in The Frogs by Aristophanes, where the Mystae (mystics) invoke him as a riotous dancer in the meadow, attended by the Charites, who "tosses torches" and is likened to a star bringing light to the darkness of the rites.

Iacchus' identification with Dionysus is demonstrated in a variety of sources. In a Paean to Dionysus discovered at Delphi, the god is described as being named Iacchos at Eleusis, where he "brings salvation". Sophocles, in the Paean in the play Antigone, names the god of the Mysteries at Eleusis as both Bacchos (Dionysus) and Iacchos. The 4th or 5th century poet Nonnus describes the Athenian celebrations given to the first Dionysus Zagreus son of Persephone, the second Dionysus Bromios son of Semele, and the third Dionysus Iacchus:
 * They [the Athenians] honoured him as a god next after the son of Persephoneia, and after Semele's son; they established sacrifices for Dionysos lateborn and Dionysos first born, and third they chanted a new hymn for Iakkhos. In these three celebrations Athens held high revel; in the dance lately made, the Athenians beat the step in honour of Zagreus and Bromios and Iakkhos all together."

The word Iacchos also signified the ritual cry ("Iacchus, O Iacchus!") that accompanied the festival. In Euripedes' The Bacchae, according to the translation by Philip Vellacott, the Bacchants call to dance, crying out in unison on the son of Zeus, "Iacchus! Bromius!". Bromius is another epithet of Dionysus.

The name Iacchos was also given to one of the days of the Mysteries: the 20th of Boedromion, upon which day Iacchus was taken from his sanctuary in Athens and escorted in solemn procession to Eleusis.

In Dion Fortune's novel The Winged Bull, the main character invokes the name of Iacchus when he is unsure what to call a particular god he wishes to summon.

The god is also referenced in the novel Lady Chatterley's Lover by D. H. Lawrence. The character Connie yearns for the passion felt by Iacchos and the Maenads.