Children of Zeus in the Homeric Hymns. Generational Succession by Nancy Felson

Random thought: this is an obvious observation to make, but the prophecies Kronos and Zeus receive as regards their threatening offspring are not really equivalent and there are meaningful differences between them.

When it comes to Kronos, the prophecy is very general: „For he had learned from Earth and starry Heaven That it was fated for him, powerful though he was, To be overthrown by his child, through the scheming of Zeus.” (Hesiod, Theogony)

Ignore the „through the scheming of Zeus” part because that is most probably just Hesiod clarifying things for us, the audience. Here is another variant: „… since both Earth and Sky foretold him that he would be dethroned by his own son, he used to swallow his offspring at birth.” (Apollodoros, Library); And another: „There was delivered to Kronos an oracle regarding the birth of Zeus which stated that the son who would be born to him would wrest the kingship from him by force.” (Diodoros of Sicily, Library of History).

So Kronos learns that a child of his will dethrone him, no real specifics.

Compare it to this: „for it was predestined That very wise children would be born from Metis, First the gray-eyed girl, Tritogeneia, Equal to her father in strength and wisdom, But then a son with an arrogant heart Who would one day be king of gods and men.” (Hesiod, Theogony)

Another account: „… after having the girl who was due to be born to her, Metis would give birth to a son who would become the ruler of heaven. (Apollodoros, Library)

Notice how Zeus himself is not actually mentioned here? The prophecy is about the goddess's children, not necessarily about his. Also notice the precise details. We know the number of children she is going to have, that her son is the dangerous one, and that the son would be born after a daughter.

In another variant (Hes. Fr. 343) things are more vague and Zeus fears that she might bring forth something stronger than the thunderbolt, but we also have a variant (schol. bT ad Il. 8.39) where he cannibalizes the pregnant Metis even though her child is not his. Interestingly, in this account she is pregnant by the Kyklops Brontes, whose name happens to mean „Thunder” and who is one of the beings who create thunderbolts for Zeus.

Let's also look at another prophecy: „Wise Themis spoke in their midst and said that it was fated that the sea-goddess [Thetis] should bear a princely son, stronger than his father, who would wield another weapon in his hand more powerful than the thunderbolt or the irresistible trident, if she lay with Zeus or one of his brothers.” (Pindar, Isthmean 8)

There are far more mentions about this son of Thetis in ancient Greek literature than there are about Metis and hers, way too many to talk about all of them here, but this one example should suffice. The prophecy is specifically about Thetis herself, and that is why making it so that her child is conceived by a mortal man fixes the issue.

TL;DR: The prophecy Kronos receives is about himself and his own child, the most specific detail he gets in some variants is that it will be one of his male offspring. The ones received by Zeus are about one of his (actual or potential) sexual partners and their sons. Kronos is at such a clear disadvantage here.

In Homeric Hymn 3, just before she leaves Olympos and asks the older gods to grant her a child more powerful than Zeus, Hera recounts how Thetis saved Hephaistos (whom Hera had thrown into the sea) and wishes that Thetis had done the gods some other favour.

Some have taken this, combined with the fact that the son of Thetis was to be stronger than his father and that Hera had raised her (described with the same words used in the Theogony to describe Gaia's nurture of Zeus), to possibly mean that Hera might actually have wanted Thetis to bear to Zeus that one son greater than his father.

Now I'll say that I find this an intriguing interpretation, but I'm not really convinced for a few reasons:

“Wherefore the kingly lineage of Gods begins in truth from Phánîs (Φάνης), coming down to our lord Diónysos (Διόνυσος), and advancing the same scepter from on high even to the furthermost dominion; only Krónos (Κρόνος), allotted the fourth kingly rank, beside all the others (received it) in a wanton manner, as imagined in the mythic pretext, and (receives) from Ouranós (Οὐρανός) the scepter and transmits it to Zefs (Ζεύς); for Nyx takes it of herself from Phánîs (who yields it) purposely: ‘He laid his glorious staff in the hands of the Goddess Nyx, so that she receive the entire dominion.’ “And from the free will of Nyx, Ouranós received dominion of the universe.”

-Orphic Fragment 101

"A pattern begins to emerge here that will become more evident and more elaborate in each subsequent episode of the succession myth: the generative principle, identified with the female, promotes change, as Gaia does here when she instigates the plot against Uranus and encourages her youngest son Cronus to depose his father. This continual impetus for change constitutes a radically destabilizing force in the cosmos. Gaia will always be on the side of birth and of the younger against the older generation. Moreover, once set in motion, there seems to be no inherent reason for this cosmogonic process to stop. Left to itself, procreation would continue, infinitely multiplying and proliferating without brakes. Countering this force for constant change, however, is the male principle, first embodied in Uranus, that attempts to discourage birth and unlimited fertility and to block generational change and the instability it entails. In fact, the history of the gods as a whole can be viewed as an account of the various attempts on the part of the supreme male god to control and block the female procreative drive in order to bring about a stable cosmic regime. Thus Uranus tries to keep his children from being born while Cronus swallows them at birth. Both attempts are of course foiled by the guiles of Gaia. Only Zeus succeeds by pre-emptively swallowing Metis, Guile personified, and thereby incorporating the female principle within himself. The opposition of violence (bie) and guile (metis) as vehicles promoting succession are already visible in the first instantiation of the repeated pattern. But while bie appears to be the prerogative of the male, and metis belongs to the female sphere, males like Cronus and Prometheus, who share the epithet ankulometis, “with crooked metis,” also make use of cunning with limited success. For each act of trickery (Cronus’ swallowing of his children, Prometheus’ attempt to deceive Zeus) provokes a counter-deception. The chain of violence and deception only comes to an end with Zeus’s complete absorption of metis/Metis."

- Hesiod's Cosmos by Jenny Strauss Clay

“The particular problem I wish to address using this approach to Hesiod's text is that of the' relationship between the overthrow of Kronos and the Titanomachy. The battle between the Olympians and Titans is explicitly referred to four times in the course of the Theogony: in the Titanomachy proper (617-720), in the hymn to Styx (390-92), at the beginning of the Typhonomachy (820), and in a brief epilogue to the Titanomachy which is deferred until after the fall of Typhoeus (881-85). It is remarkable that not only do we never hear of Kronos in any way taking part in this Titanomachy, but once the narrative of his deception by Zeus is broken off so abruptly at line 500, we in fact never hear of him again. If Hesiod imagined him to be a combatant in the Titanomachy, why is his role never mentioned? Admittedly none of the Titans is mentioned specifically by name in the Titanomachy itself (and traditionally they may not even have had individual names)~ but Kronos has after all been portrayed as the (earlier king of the gods), and we might expect that at least the leader of the enemy forces would be singled out for mention in the narrative of this conflict, especially since it would be the very conflict in which he was forced from the throne. If, on the other hand, we are to assume that Kronos had somehow already been eliminated by Zeus as a result of the events in lines 453-500 and therefore was not one of the participants in the subsequent theomachy, why was this earlier elimination not made more explicit? In either case the sudden disappearance of Kronos from the narrative is puzzling in the extreme: the elevation of Zeus to the throne previously held by his father is by every critic's reckoning the climactic moment in Hesiod's vision of divine history; yet in the text of his poem it is not at all clear at what point this climactic moment actually occurs. Previous attempts to resolve the problem posed by this double narrative of Zeus' rise to power illustrate the kinds of arguments employed by the critic who wishes to see the Theogony as a synchronic unity and at the same time cast the most favorable light on Hesiod's narrative ability. According to Solmsen, for instance, Hesiod "draws us into the atmosphere of Zeus' reign long before it is finally and securely established; he unfolds it by degrees and guides us to the realization of its existence before it is historically achieved." An alternative means of forcing synchronic logic on the text is to suppose that the Titans are actually rebels against a Zeus already in power: so Paley spoke of the "acts of Zeus in punishing rebels against his authority." But neither Hesiod's text nor the subsequent Greek literary tradition will support this notion: the Titans are the "former gods" who are now in Tartaros, and the Olympian hierarchy is not in place until after they are deposed as a result of the Titanomachy. If anything, it is Zeus and his allies who are the rebels against established authority.

This twice-told tale of Zeus' acquisition of the kingship is just the sort of narrative doubling that we would expect when diachronically independent traditional material is combined in a non-traditional complex. I suggest that we have here the Hesiodic juxtaposition of two previously independent songs representing mutually exclusive traditions. Each presents a different mythological narrative of Zeus' rise to power, in one case through the patrilinear succession Ouranos-Kronos-Zeus, with never any question about who the leader of the new generation would be (453-500), and in the other case as the result of a general theomachy in which the new gods as a group oust their predecessors and establish Zeus on the celestial throne (617-720). . . . In sum, the Titanomachy and the hymn to Zeus, as they appear in the Theogony, present diachronically independent mythological narratives, and as late as Hesiod's time there was not yet any established tradition for combining them. Perhaps the coexistence of such alternative myths has a regional explanation; in any case, in creating his Panhellenic theogony Hesiod himself has simply placed these two songs in sequential juxtaposition, according to the compositional principles outlined in part I. Consequently, it is pointless to try to understand or reconcile them synchronically. Hesiod does not mention Kronos in the Titanomachy because traditionally Kronos did not play any outstanding role there, just as the Titans did not figure in the alternative tradition, based on the Hellenized Hittite myth, of Zeus' birth and single-handed expulsion of his father. That Hesiod's combination of the two songs is a non-traditional one is indicated not only by the fact that the contents of the two songs are simply juxtaposed in the Theogony rather than conflated (as we might expect to have happened during transmission over a longer period of time), but also because when such a conflation does inevitably occur in postHesiodic sources, both possibilities inherent in Hesiod's ambiguous narrative are realized: in some cases Zeus first disposes of Kronos separately and then goes on to fight the Titans, in others the outwitted Kronos joins with the Titans in battling Zeus and his newly liberated siblings. We may now answer the question raised at the outset about the sudden disappearance of Kronos from the main narrative thread of the Theogony. Any self-contained realization of the hymn to Zeus surely would have concluded with an explicit statement of the transfer of celestial authority after Kronos released his children and was overcome by Zeus. But Hesiod is here faced with the same dilemma as earlier when he inserted the abbreviated narrative about the children of Styx. Any explicit depiction of the transfer of power at this point in the Theogony would render a subsequent narrative of an alternative tale of Zeus' rise to power-the Titanomachy-nonsensical. So Hesiod made at least a rudimentary attempt to preserve a degree of narrative flow in his composite Theogony by suppressing the end of the first of these two juxtaposed narratives. The outcome of the deception of Kronos-the enthroning of Zeus and the distribution of timai simply passed over in silence, and Zeus does not explicitly assume the reins of power and redistribute the divine prerogatives until lines 881-85 - that is, not until after the second of these two narratives describing how he attained them.”

 - The Ascension of Zeus and the Composition of Hesiod's Theogony  by Robert Mondi 

“So is it possible to say anything meaningful about their common nature, beyond the fact that they are the banished ruling gods of an earlier generation? This was once a question that gave rise to a considerable amount of speculation. A much-favoured theory suggested  that the Titans were old prehellenic gods who had been displaced by the Olympian gods of the Greek invaders. If that were so, the myth of the great war between the Olympians and the Titans could be explained in historical terms, as reflecting  the struggle of belief that the suppression of the older religion had entailed. It was often proposed, furthermore, that the old gods must have been nature-powers of a less advanced or less moral nature than the Olympian gods. Another theory appealed to late evidence of doubtful value to suggest that the Titans were phallic deities. The whole nature of the discussion altered, however, when it came to be realized that the Greek succession myth bears a marked resemblance to myths of a comparable nature from the ancient Near East. Although other eastern succession myths had been known at an earlier period, the crucial factor in this regard was the publication in 1946 of a Hurro-Hittite myth that provides a particularly close parallel to Hesiod’s myth.

The Hurrians, an ancient people who lived in northern Syria and adjoining areas, were subjugated in the fourteenth century BC by the Hittites, who were much influenced by their culture and have transmitted some of their myths to us on cuneiform tablets. One such myth tells of the sequence of events that led to the accession of the Hurrian equivalent of Zeus. Anu (Sky), who corresponds to the Greek Ouranos, seized power by deposing an obscure predecessor, Alalu, and reigned for nine years until his cupbearer, Kumarbi, engaged him in battle and defeated him. As Anu was trying to escape into the heavens, Kumarbi dragged him down by his feet, and  bit off his genitals and swallowed them. As he was then rejoicing in his triumph, Anu warned him to think again, saying that his action had caused him to become impregnated with three terrible gods. Although Kumarbi immediately spat out the contents of his mouth, the Storm-god was already inside him, and eventually emerged from his body. The text is very defective from this point onwards, but it is clear enough that the Storm-god, who was the main god of the Hurrians and Hittites just as Zeus was the main god of the Greeks, finally displaced Kumarbi  as ruler. Hesiod’s myth may also be compared with a very ancient Babylonian myth in the poem known as the Enuma Elish, and also with a Phoenician myth  (of questionable status, but thought to be at least partially authentic) which is preserved in a Greek work of the early Roman period.

When the implications of these foreign parallels came to be appreciated, it came to be generally accepted that the Greek succession myth was not of native origin, but was based on a myth that had been introduced from the Near East. If this was the case, a group of displaced earlier gods corresponding to the Titans must have been introduced as part of the imported myth. The Hurro-Hittite equivalents of the Titans were known as the former gods (Hesiod refers to the Titans or Kronos in corresponding terms on two occasions), while their Babylonian equivalents were known as the dead gods. If the question of the origin of the Titans is viewed from this perspective, two possibilities arise. There may have been an early group of native gods of that name who were identified with the former gods of the imported myth; or else the name Titan was simply a title that was applied by  the Greeks to the gods of eastern origin. There is no way of telling which alternative is true, and it makes little practical difference in any case, since we know nothing whatever of the original nature of the Titans if they had once enjoyed a separate existence in Greece. The essential point is that the Titans, as they are known to us as a collective body from the time of Hesiod onwards, are precisely what they are presented as being in the succession myth of eastern origin, the former ruling gods who were banished from the upper world when the present divine order was established. This is their ‘nature’, and nothing is served by enquiring any further; they have no other stories or functions as a collective body in conventional myth, and they had no place in Greek cult. The etymology of their name is uncertain; there is some ancient evidence to suggest that it may have meant ‘princes’ or the like. Hesiod offers an ingenious but obviously factitious double etymology, stating that Ouranos conferred this title on them in reproach, ‘for he said that they strained (titainontes) and insolently performed a dreadful deed, for which vengeance (tisin) came tto them afterwards’.”

 - The Routledge Handbook of Greek Mythology, Robin Hard