Everybody has heard of Pan, and would even know him if they met him. A Greek god with the physique, not of a Greek god, but of a small man with a goatee beard and reed pipes, and the hind-quarters, horns and sexual habits of a goat.
We know about Pan because his worshippers were civilised, and wrote everything down, and so we have entire books of Greek myths, and Pan pops up in them everywhere. We know nearly everything about him, from his parentage, birth and childhood (the foster brother of Zeus himself), through numerous adventures right up to his (supposed) death. In fact so much Greek writings survive that there are several versions of nearly everything about him.
The other gods often referred to him as the youngest of them, but he was probably the oldest, having been first worshipped in Arcadia, where he was certainly being worshipped as early as the 6th century BC. This fertile plateau lies in the South of modern Greece, and there lived the pastoral ancestors of the heroes who later built the Greek empire. Pan was born there, on Mount Lycaeum, and in the hearts of a shepherding people who depended a lot on goats, and so naturally needed a goat-god.
Even after the Greeks became civilised and had new civilised gods to pray to, they never forgot old Pan, and built shrines to him everywhere. There is even one hidden away in a shallow cave under the Acropolis, in a suitably wild and unkempt place.
They must still have regarded him with affection well into Christian times.
Daphnis, I that piped so rarely,
I that guarded well the fold,
'Tis my trembling hand that fails me;
I am weary, I am old.
Here my well-worn crook I offer
unto Pan the shepherd's friend;
Know ye, I am old and weary;
of my toil I make an end!
Yet I still can pipe it rarely,
still my voice is clear and strong;
Very tremulous in body,
nothing tremulous in song.
Only let no envious goatherd
tell the wolves upon the hill
That my ancient strength is wasted,
lest they do me grievous ill.
Macedonius: 6th century A.D.
Pan had many attributes as a god. He was the god of goats, and sheep, and their shepherds. He was the god of bee keeping. He was also a god of music, playing upon the reed pipes he made from the transformed body of the nymph Syrinx (the one that got away). It was said that this music could inspire panic (the root of the word) in any who heard it. Sometimes he was a minor god of the sea. He was a god of prophesy and was also famous for being randy (Greek women with a track record were known as Pan girls). Above all he was the god of nature: meadows, forests, beasts, and even human nature.
To Pan and the Dryads here
I dedicate my hunting spear,
My dog, the bag that holds my store;
I am too poor to offer more!
Nay, but my dog I cannot spare!
He must return my crusts to share,
My daily rambles to attend,
My little comrade and my friend.
Macedonius: 6th century A.D.
Unlike the other, more heroic Grecian deities, Pan's adventures tended toward the comical. King Midas (after his recovery from the gilding incident) was asked to judge a musical contest between Pan and Apollo. When he chose Pan, Apollo punished the king by giving him the ears of an ass.
In another farce Pan was in persuit of Omphale, the queen of Lydia, but on the crucial night she had swapped clothes with Hercules (don't ask) and so Pan mistakenly got into bed with him instead and got kicked across the room. After that he banned all clothing at his religious rites and spread rumours that Hercules was a transvestite.
Pan's worship spread far beyond Greece into many neighbouring countries such as Egypt, and local equivalents of him seem to have appeared all over the world, either by diffusion or coincidence. Pan-like deities existed everywhere. In Greece there were rustic gods such as Aristaeus (flocks, agriculture, bee-keeping, vineculture), Priapus (the same) and Silenus (vineculture and knowledge).
Then there were the satyrs, an entire race of Pan-like beings, who lounged in woods and by streams, eating, drinking and fornicating, and not much else. The Romans called them incubi or fauns, and the iron age Celts were said to believe in dusii. These were not gods but nature spirits, and were not worshipped but only believed in, and perhaps propitiated.
The Greek gods became adapted into Roman gods, and changed and flowed, the way gods do, living in the stories and myths that keep them immortal. Some are forgotten, others sleep for a while, but only rarely do gods actually die. There is only one story about the death of a Greek god, and it is Pan.
Plutarch wrote that in the reign of Tiberius a sailor passing by the Echinades islands heard a mysterious voice call out three times "when you reach Palodes proclaim that the great god Pan is dead".
Of course, he isn't.
"Pan: Great God of Nature" by Leo Vinci (Neptune Press, ISBN 0-950-50018-6)
"Greek Myths" by Robert Graves (Book Club Associates)