From The Dawn of Everything- A New History of Humanity by the anarchist anthropologist and archaeologist team Graeber and David Wengrow explaining about how people began to be used as labor for Egyptian pyramid construction:

What preceded the First Dynasty, then, was not so much a lack of sovereign power as a superfluity of it: a surfeit of tiny kingdoms and miniature courts, always with a core of blood relatives and a motley collection of henchmen, wives, servants and assorted hangers-on. Some of these courts appear to have been quite magnificent in their own way, leaving behind large tombs and the bodies of sacrificed retainers. The most spectacular, at Hierakonpolis, includes not only a male dwarf (they seem to have become a fixture of courtly society very early on), but a significant number of teenage girls, and what seem to be the remains of a private zoo: a menagerie of exotic animals including two baboons and an African elephant. These kings give every sign of making grandiose, absolute, cosmological claims; but little sign of maintaining administrative or military control over their respective territories.

How do we get from here to the massive agrarian bureaucracy of later, dynastic times in Egypt? Part of the answer lies in a parallel process of change that archaeology also allows us to untangle, around the middle of the fourth millennium BC – we might imagine it as a kind of extended argument or debate about the responsibilities of the living to the dead. Do dead kings, like live ones, still need us to take care of them? Is this care different from the care accorded ordinary ancestors? Do ancestors get hungry? And if so, what exactly do they eat? For whatever reasons, the answer that gained traction across the Nile valley around 3500 BC was that ancestors do indeed get hungry, and what they required was something which, at that time, can only have been considered a rather exotic and perhaps luxurious form of food: leavened bread and fermented wheat beer, the pot-containers for which now start to become standard fixtures of well-appointed grave assemblages. It is no coincidence that arable wheat-farming – though long familiar in the valley and delta of the Nile – was only refined and intensified around this time, at least partly in response to the new demands of the dead.

The two processes – agronomic and ceremonial – were mutually reinforcing, and the social effects epochal. In effect, they led to the creation of what might be considered the world’s first peasantry. As in so many parts of the world initially favoured by Neolithic populations, the periodic flooding of the Nile had at first made permanent division of lands difficult; quite likely, it was not ecological circumstances but the social requirement to provide bread and beer on ceremonial occasions that allowed such divisions to become entrenched. This was not just a matter of access to sufficient quantities of arable land, but also the means to maintain ploughs and oxen – another introduction of the late fourth millennium BC. Families who found themselves unable to command such resources had to obtain beer and loaves elsewhere, creating networks of obligation and debt. Hence important class distinctions and dependencies did, in fact, begin to emerge, as a sizeable sector of Egypt’s population found itself deprived of the means to care independently for ancestors.

Even if the actual guys that moved it weren’t slaves, calling the other people involved not slaves is crazy. The society existed on the backs of slaves