Hades - the only Greek God worth your time.

The pre-history of the Greek Gods is simple. Grandaddy Uranus was a bad father who came home drunk and had loads of kids and beat them every night. By "beat them", I mean "locked them in his underground lair". I'm not sure he was a drunk, but he was mighty pissy for sure.

The kids, eventually dispatched with him, and the oldest of them, Cronus, started a patriarchal autocracy of his own. Like father, like son. Except Cronus didn't lock his kids up.

He ate them.