Dionyssos was the god of fertility and wine. The etymological structure of the name can give us a lot of information as far as the origin of the cult is concerned. "Dionyssos" consists of two components: "dios"and "Nyssos". Dios is the genitive of Zeus, which exact translation would be: Zeus's."Nyssos" is a word of frygic-thacic origin, synonym of the word "kouros". So Dionyssos is the Kouros of Zeus-the son of Zeus.
In Thrace, Dionyssos was considered to be the god of fertility and he was worshiped with orgies and ceremonies not compatible with the greek tradition. As his worship spread to the South met with the greek worship of Dionyssos, where he was considered as the god of wine. The two forms of the same worship got mixed and the new worship of Dionyssos, the god of fertility and wine got born.
The oracle of Delphi had a great contribution to the stabilisation of the new worship, because Dionyssos was believed to have prophetical competence, long befor Apollo. Both gods were so important in Delphi, that the delphic year was devided in two periods, the dionyssiac and the apollonian.
In Athens, special festivities were organized to praise the god : the Small and Great Dionyssia.
There are many legents about the birth of Dionyssos. The dominant ome is that Dionyssos was born in Thebes. He was the son of Zeus and Semeli, daughter of Kadmos, king of Thebes. Hera, wife of Zeus, jalous because of the affair between her husband and Semeli, convinced Semeli to beg Zeus to appear in front of her in all his power. He did her the favour and he appeared accompanied by thunders. Semeli's house got fire and she died. Before she died she gave birth to the embryon Dionyssos(therefore Dionyssos was called:"pyrigenes",which means born in fire).Zeus took the embryon and put it inside his thigh, until the day of his birth (Some believe that the surname "dithyrambous",attributed to Dionyssos is due to this double birth of the god-Dithyrambous=dyo+thyra : from two doors).
After the 6th century BC the cult of Dionyssos had conquered the whole of Greece. The elements of extasis and mysticism, that can easily be observed in dionyssiac orgiastic ritual celebrations are not of greek provenance. They had been transfered from the frygic-thracic cult of Dionyssos.
The most important element of that new worship was the exaltation of the soul, that reaches the point of enthousiasm, which is expressed by rapid movements of hands and body and by hysterical screamings.Women that had dedicated theiselves to the god were moving around with pinewoods in their hands, so that they could lighten their way through the woods, where they were following by night their invisible guide, god Dionyssos. In return, Dionyssos filled their souls with physical and spiritual pleasures and at the same moment their souls are purified and exalted to the perfection of a surernatural life.
In another version of the legend, Dionyssos conquered the immortal happiness through sadness and death. According to the ideas of the orphics, Dionyssos symbolizes the everpowerful life. During the rituals and the orgies Dionyssos was called back from the dead by his followers. As we can see there is a strong bond between the legend of Dionyssos and the legend of Demetr and Persephone. The worship of these three gods was transfered as one to greek South Italy and later on to the Romans.
The dionyssiac ceremonies, simple at the beginning, little by little became noisy and orgiastic. The enthousiasts were strolling holding the phallus in front of them, accompanied by flute,drums and forminx, eating the raw fleshes of the animals sacrificed to Dionyssos.
The festivities for the celebration of Dionyssos were called "dionyssia"