Why was there never an Ancient Egypt theme?

Before you say it, yes, I am aware of both Adventurers and Pharao's quest. That's not what I'm talking about, those are modern day characters exploring ancient ruins. What I mean is a theme that is actually set in ancient times. We have had several "ancient" themes such as Castle, Pirates, Vikings, Western or Ninja, so why not Ancient Egypt?

I also know there are several minifigures of mummies or pharaos, so it's not like Lego is completely avoiding it. Same question for Roman Empire. Why not?