There are many myths surrounding the birth of Dionysus. The most common myth goes as follows: Dionysus is the son of Zeus and Semele, the daughter of Cadmus, the founder of Thebes. When Hera learnt that Semele was pregnant by her own husband, Zeus, she, overcome with jealousy, tricked Semele into seeing Zeus in his divine form. Semele had made Zeus promise to grant her any wish, and subsequently suggested the very thing Hera had demanded.
Zeus appears to her in a blaze of lightning, and Semele dies in the flames. Zeus removes the unborn child from the woman’s womb before it is consumed by the fire, sews it into his own thigh, and, when the time comes, brings about the birth of Dionysus. This explains why Dionysus is referred to as the "twice-born god".
Fearing Hera, Zeus entrusts the infant, named Dionysus, to Hermes. Hermes takes the infant to Ino, Semele’s sister. In response, Hera drives Ino and Athamas mad as a punishment. After Ino and Athamas were driven mad, Dionysus was entrusted to Papposilenos (the Chief Silenus) and the Nymphs of the Nysa Valley.
The nymphs, water spirits, abducted the infant Dionysus from Hera and brought him to the ancient city of Nysa, located in Western Anatolia, in the vicinity of present-day Aydın / Sultanhisar, in the Great Menderes River Valley, and raised him in the fertile lands of the Aegean Region, irrigated by the Menderes River and adorned with vineyards and olive groves.
Dionysus is regarded as the god of nature, the grape, the vine, intoxication, and even theatre. He featured in festivals aimed at achieving a joyful union with nature.
In Athens, the Rural Dionysia were held at the end of December, the City Dionysia in late spring, the Anthestheria in early spring, and the Lenaia in January. These festivals took place within the context of the birth and death of nature.
According to them, this god of nature had spent the winter in slumber and awoken in spring; the people celebrated his awakening and his subsequent death in autumn as a religious festival. During these festivals, people would abandon themselves to unrestrained intoxication amidst the sounds of drums and trumpets and the melodies of flutes.