I'll leave the explaining things about Greece to you. I was around at the time, but I was mostly in the Dream World. I spent most of that period arguing with philosophers from across the world and working on my own projects. Also, there weren't any actual Greek Gods running round, just stories about them, so I'll have to defer to you on those. I do know the stories, but there'll probably be some major divergences from this world if there isn't a Dream World like mine.