Trying to find the identity of a book series

Hey everyone, I apologize in advance if I posted this in the wring place but it's something that I've been trying to figure out all day and been unable to find an answer to.

So, for whatever reason, today I remembered a book. A book I never read, but only saw the synopsis and cover of. Now, this book was one in a "series" from what I had gleamed, one that would take ancient civilizations (say, the Roman Empire) and give them some kind of ASB advantage that made them just incredibly powerful (I think the one on the Roman Empire involved them getting modern technology). The running theme through this, being ASB, was that it involved Gods or, more accurately, aliens posing as Gods.

Now, this series, whatever it was, had a book about the Aztecs (or some Mesoamerican culture but I am very positive. It was Aztec). And, in this book, the Aztecs get a technological/societal 'uograde' when an alien race encountered them. Specifically, and this is the thing that sticks out the most to me, an alien race that resembled Spiders, with the cover showing a kind of Spider like monsters head sticking uo above a jungle with your standard ziggurat.

And now, for whatever reason, my mind is focused—obsessed even—with this, and try as I might, I can't find anything. So, does anything I'm saying here sound familiar to anyone?
 
Top