Dionysus-God of Wine, Vegetation, and Human Emotion

Dionysus was the son of Zeus and Semele, a mortal daughter of Cadmus king of Thebes.  Hera, Zeus's wife tricked Zeus into killing Semele accidentally with his lightening bolts.  Zeus, not wanting his child to die with its mother, he snatched the unborn baby from the ashes of Semele's body and sewed it into his own thigh.  Zeus eventually gave birth to his twice born son.  After that Dionysus was considered the god of double birth.  He was half mortal but made wholly divine at his birth since his mother's mortality had burned away.  

Hera could not be stopped though.  She sent the Titans to eat baby Dionysus.  They tore him limb from limb and were about to cook him when Rhea intervened and disguised him as a girl and took him to the court of Athamas, king of Orchomenus in Greece.  Hera made Athamus go mad, so yet again Dionysus was on the run.  Eventually raised by mountain nymphs in Phrygia, and later moved to Thrace.  

The fact that Dionysus always had to run to far off places with little civilization was a critical aspect of the cult of Dionysus.  He represented the ancient YOLO as the kids say, inspiring people to let go and be free, acting as if no one was watching them.  Hence why he is likely associated with wine and alcohol with loosens inhibitions. 

God of Wine and Emotion

Dionysus especially cared for the grapevine, the source of wine.  He taught the Athenians the art of wine making.  Dionysus also cared for the aspects of instinct, self indulgence, excitement, and freedom.

Dionysus in Art

Dionysus is often depicted with a small band of satyrs.  These creatures enjoyed drinking, chasing nymphs, and leading a wild life.  He was the god most frequently shown in ancient art.  Essentially Dionysus embodied what it meant to be Greek.  He displayed the joy, happiness, and freedoms they were all about.