He was the god of fertility and wine, later considered a patron of the arts. He invented wine and spread the art of tending grapes. He has a dual nature. On the one hand bringing joy and devine ecstasy. On the other brutal, unthinking, rage. Thus, reflecting both sides of wines nature. If he choses Dionysus can drive a man mad. No normal fetters can hold him or his followers.
Dionysus is the son of Zeus and Semele. He is the only god to have a mortal parent. Zeus came to Semele in the night, invisable, felt only as a devine presence. Semele was pleased to be a lover of a god, even though she did not know which one. Word soon got around and Hera quickly assumed who was responsible. Hera went to Semele in disguise and convinced her she should see her lover as he really was. When Zeus next came to her she made him promise to grant her one wish. She went so far as to make him swear on the River Styx that he would grant her request. Zeus was madly in love and agreed. She then asked him to show her his true form. Zeus, was unhappy, and knew what would happen but, having sworn he had no choice. He appeared in his true form and Semele was instantly burnt to a crisp by the sight of his glory. Zeus did manage to rescue Dionysus and stiched him into his thigh to hold him until he was ready to be born. His birth from Zeus alone conferred immortality upon him.
Dionysus problems with Hera were not yet over. She was still jealous and arranged for the Titans to kill him. The Titans ripped him into to pieces. However, Rhea brought him back to life. After this Zeus arranged for his protection and turned him over the mountain nymphs to be raised.
Dionysus wanderes the world actively encouraging his cult. He was accompanied by the Maenads, wild women, flush with wine, shoulders draped with a fawn skin, carrying rods tipped with pine cones. While other gods had templaces the followers of Dionysus worshipped him in the woods. Here they might go into mad states where they would rip apart and eat raw any animal they came upon.
Dionysus is also one of the very few that was able to bring a dead person out of the underworld Even though he had never seen Semele he was concerned for her. Eventually he journeyed into the underworld to find her. He faced down Thanatos and brought her back to Mount Olympus.
Dionysus became one of the most important gods in everyday life. He became associated with several key concepts. One was rebirth after death. Here his dismemberment by the Titans and return to life is symbolically echoed in tending vines, where the vines must be pruned back sharply, and then become dormant in winter for them to bear fruit. The other is the idea that under the influence of wine, one could feel possessed by a greater power. Unlike the other gods Dionysus was not only outside his believers but, also within them. At these times a man might be greater then himself and do works he otherwise could not.
The festivel for Dionysus is in the spring when the leaves begin to reapper on the vine. It became one of the most important events of the year. It's focus became the theater. Most of the great greek plays were initially written to be performed at the feast of Dionysus. All who took part writers, actors, spectators were regaurded as scared servents of Dionysus during the festivel.