The "slaves built the Pyramids" thing has been pretty well-debunked by anthropologists and archaeologists, who both agree that something as monumental as building the vehicle of the Pharaoh's ascent to the afterlife would not have been something Egypt would've forced slaves to labor on. Aside from the obvious chances of revolt, there's a lot of religious reasons, and many agree that it was likely seen as a GREAT honor - backed up by inscriptions of the masons that worked the stone (found in some reliefs), or painters, etc. It's not unlikely that they used slave labor to quarry and transport the stones to the building site, but not to actually physically haul and build things AT the site.