Reading David Graeber made me feel a hankering for some info about ancient times, so I decided to go with the basics and read the translation of Herodotus that I've had on my kindle for three years. In a very broad and sprawling way, this is basically a history of early Greece and its wars with Persia. And it's the major source for much of what we know about the period. I believe the story of King Leonidas and the three hundred originates in Herodotus, for instance.
Herodotus is fascinating. He has a reputation for being pretty off-the-wall and not nearly so careful and fact-based as the other great Greek historian, Thucydides. Herodotus is basically repeating stories that he's heard. Many of the stories shade into legend. There's lots of intervention by Gods and consulting divine oracles and princes being rescued by kind shepherds and raised as their own.
But it's also, just as clearly, not a work of mythology. Herodotus is trying, to some extent, to convey the actual things that he believes (or at least hopes) actually happened. And this is evident in much of the way that he shades his tales. For instance, there are lots of stories in here about oracular prophecies that are just wrong. A king consults an oracle and get the prophecy and the prophecy turns out to be straight-up false. And then Herodotus is like, "Welp! Guess that was a false oracle then!"
That's the kind of gritty little fact that you don't generally see in a work of myth.
So far, my favorite part was when King Croesus of Lydia decides to set up a test to see which of the oracles is a real oracle and which is a false oracle. He basically sends messengers to all the oracles and gives them instructions to ask them, on a particular moment of a particular day, what Croesus is up to. And then they're to bring their answers back to Croesus so he can compare them and see who got it right. Now that is a pretty neat story. You gotta wonder why none of the ancient Greek heroes bothered to do something like that.
Also, you know the thing that Croesus chooses to do on that day? He cuts up some turtles and makes a stew. Yes, the winning oracle was the one who gave him a poem that said, more or less, "King Croesus is making turtle stew right now."