An Egyptian pyramid is a very clear statement: it is a picture of a society, stressing its hierarchy. Like society, every higher layer of the building rests on, is supported by, a layer below it which is larger in size. The golden top, where earth meets heaven, represents the Farao. This is fitting since the Egyptian ruler is a god on earth. Such is the picture, carved out in stone, of a society ruled by a divine King: everyone is below him, conceptually his slave.
There are other possibilities for organizing a society. Historically it looks like in the Middle East there was one choice: kingdom or independent city states. Egypt always chose kingship and the scribes tell us they were happy with that. Whenever great and divine kings arose in, for instance, Assyria or Babylon, smaller states trembled because they knew what was going to happen. The choice that Israel made (before the time of Saul and David) was a kingless society. A topless pyramid as it were, still hierarchical on the lower levels but not all the way to the top. The implicit top of this pyramid, the divine ruler to be obeyed is in heaven, is "virtual"(1), and, this must be emphasized, never comes down to earth (at most to a mountain top). It is no less important to obey him, though. This is the rule of Zeus. There still is a ruling class, they are conceptually all equal (the highest layer of the topless pyramid), and free.
In any larger, hierarchical society, there is tension between the very top (the King) and the layer below it (the aristocracy). The latter desires to be free of Kingly rule, it is usually only because of the threat of war, the need for a leader, that they tolerate kingly rule at all. The bottom layer (the common people) are ruled or exploited by the aristocracy and desire to be free of them. Often the common people regard the King as an ally against their local rulers(1). Since all three layers of society have a power of their own which varies but is not to be ignored, there exists a love triangle which can be found all through history.
So both types of society, the "divine king" model and the "topless
pyramid" have their intrinsic problems. The Greeks, who in their Myceanean
past had divine kings (as far as we can tell) were in Homer's day
working on the establishment of a model of independent city-states
and no King. No gods on earth. How is it possible to get local
rulers to cooperate to maintain such a system?
I think it is possible, even likely, that they learned from the Phoenicians, probably via high-level aristocratic contacts, how to go about it. There are some clues which point in this direction. Phoenicia (Tyre) was the place where they could teach you how to build a temple (ref. Solomon) and how to write down your language using an alphabet. If you wanted to pacify a region by non-military means, you needed something else to unify it while preserving local independence: myth and religion. For this you need shared religious narratives and practices so there would at least be a feeling of cultural unity. Ergo the temples, most importantly Delphi, and the alphabet which was used more and more to spread culture, witness the rise of self-defining (Homer) and didactic (Hesiod) poetry and some Homeric Hymns.
So why would they think this would work? Presumably they would go to war with each other until one came out on top, proclaiming himself King. If no one was strong enough for that, that still would not stop them going to war just to get one-up on their neighbours. War, after all, is the raison d'être of an aristocracy (Il 12.310-). This situation the Greeks called 'stasis'(2). So how could this work? (spoiler: it did not)
Hesiod, in his Theogony, has the following important scene:
“[...]For so did Styx the deathless daughter of Ocean plan
on that day when the Olympian Lightning god called all the deathless gods to great Olympus, and said that
whosoever of the gods would fight with him against the Titans, he would not cast him out from his rights,
but each should have the privileges which he had before amongst the deathless gods.
And he declared that he who was without honours or right under Kronos, should be raised to both honours and
rights as is just.”
So: "Join the fight against anyone who wants be King of all and your position is safe".
Why Styx? The river Styx is the boundary between life and death. Cross it, and you are dead. An oath "on your life" is also a boundary: cross it and you are dead. Hesiod does not just tell us a myth, he tells in a "mythified" manner of a political event: the oath that underlies the reign of Zeus, a general peace treaty and the panhellenic reform. Let us draw a picture:
Mainland Greece is recovering from the so-called dark ages and there is a population explosion. Hunger for land results. Armies ('hundred-arms') are springing up everywhere(2). Large, slow movements like the "Dorian invasion" are or have been destroying the status quo. There is a real risk of prolonged civil war, a competition for power that will only end when one party subjugates all the others and declares himself king of all Hellas: a new Kronos(3). To prevent such a disaster - for there is apparently no one strong enough to win this fight outright - they create a system of freedom and equal honours (for the top layer, but it slowly trickles down), a topless pyramid. This is the reign of Zeus. They swear a solemn oath to maintain this situation because it is in their interest. It is an attempt to freeze the political situation. This is also expressed in a part of the story of Helen:
Helen(6) is not so much a woman, as she is the prize, the symbol of
Victory. That is why she must be a daughter of Zeus,
for Zeus is the one who gives victory. Sparta has won her, proving to be the strongest.
Although Menelaos' Sparta is necessarily pre-doric, that does not invalidate the picture:
Sparta is probably the most
powerful and important state at that moment - whatever that moment is. I leave it to historians
to correlate all this to a credible timeline which includes the first Messenian war. All the states have sworn
an oath to respect and defend the rights and honour of whoever would win her. This is a consequence of
the oath mentioned above: the political situation must be frozen.
Another measure they take is also meant to stabilize the situation. To relieve the burden on Mother Earth and prevent further ravaging by "hundred-arms", they institute an emigration policy. As many as possible superfluous males are to be transported out of the country(7). For a discussion of this, see here about Helen and Paris' role in this.
So the rule of Zeus was established with agreement to stand up together against anyone who would try to bring back Kronos. This seems like a simple United Nations-like treaty but the religion and the politics of a whole culture were to be reshaped to make it a reality. They did an enormous amount of work to reach this goal: regional peace treaties, the (re-)foundation of Delphi, collection and creation of a "library" of stories, genealogies, hymns and epics that could appeal to all Greeks, building of temples and religious standardization (more or less). The aim was to unify the country culturally but not politically.
All this could not hide the fact that this was a system based on voluntary compliance. Political reality remained what it always was. The Zeus option is in that reality a weaker option: unlike Zeus, Kronos rules with the whip and is more sure of being obeyed. Especially if issues arise beyond the border that call for war, absolute kingship becomes more attractive. In Greece, the Olympian system held out reasonably well until the Persian invasions, then it broke down. The creation of the Athenian empire and its war with Sparta were the result of that(8). But the Greek aristocracy knew that they had defeated the Persians twice, they could go to war and win. So they needed a Kronos: Alexander.
There must have been those who went with this Zeus rule only because it was opportune to do so. I suspect that "Poseidon", meaning the Neleid clan, followed that policy. But their organizing the Ionian migration does look like a barely disguised attempt to regain Greece-wide kingship using the rich lands of western Anatolia as a power base. Note that Poseidon, like a Kronos, does not hesitate to set foot on land whereas Zeus never comes down to earth.
It is the aristocracy that has to "hold up heaven", keep it separated from earth and prevent it from crashing down on us. This means that Atlas will have to do without the apples (and not rely on Heracles to hold it for him). To promote this there is a whole laundry list of necessary things: an arbiter for conflicts, peace and mutual-aid treaties, a sense of 'being one people', ethical re-education of local aristocrats but most of all: a fitting religion which properly defines the position of everyone in society and creates a model "as above, so below" of the world.
In the Homeric context, a commoner is typically the head of an οἶκος (household),
a landowner with extended family and
a number of people of which he is a patron: people who work for him, therapontes
(high-ranking servants), slaves, people who are dependent
on his household for a livelihood or who otherwise "owe" him. When there is a war,
he himself (or possibly his son) is to lead a contingent of these dependants into
battle. This is a private army and there are no laws to force the householder
to do this. It is in this light, I would maintain, that we have to see the Homeric picture
of Achilles and his Myrmidons. In his own household Achilles is king, but in the
polis where he lives, he has to count with others. There can be no private armies,
he has to submit some of his sovereignty to the polis and especially to the archon (whatever
his name and powers were in any city-state) that the city chooses to have: to Agamemnon.
Not because Agamemnon is 'the better man', no aristocrat would ever concede that, but
because he is the first among equals. That, at least, is the theory.
In practice of course the equals are rarely equal. The one who lives in the 'big house' can be very much a local 'king' because of his actual power, based on economic clout, tradition or religion. It would be possible for a rich farmer to force others to sell their produce to or through him, for instance if he owns a ship for trade, or has the overseas contacts, or has the storage facility. He may be harbour-master and catch a tax on incoming ships, he may have judicial authority and collect bribes. Or simply the patronage power: it was a harsh and lawless society and protection must have been important. Achilles is reminded by Nestor that Agamemnon 'is the better man, because he rules more people (Il 1.281)'.