Scholar Dorothea Clinton Woodworth, in her article "The Function of the Gods in Vergil's Aeneid," has argued that Virgil's Aeneid essentially concerns the theme of destiny and that the gods actually play a surprising role concerning the fulfillment of destiny. Contrary to what one might normally think, throughout the Aeneid, we actually see that the gods, despite what they want, actually have no ability to control destiny. What is fated to happen happens despite what the gods do and want. Scholar W. Y. Sellar particularly points out in the book The Roman Poets of the Augustan Age: Virgil that Virgil used the Aeneid to state his claim concerning the creation of the Roman Empire: The Roman Empire was not necessarily built and established strictly by humans; it was instead built by "divine purpose and guidance." In other words, it was fated to be built and the gods had no control over its destiny (as cited in Woodworth). In the Aeneid, Juno is particularly portrayed as wanting to prevent the Trojans' destiny of creating Rome because she is the patroness of Carthage and because she hates the Trojans due to having lost a beauty contest that Paris judged. However, despite wanting to prevent the creation of Rome, she is unsuccessful, and by Book XII, at Jove's request, she finally submits to fate and relinquishes her hatred of the Trojans, so long as the name of Troy will be erased and the people conquered shall continue to be called Latins. Hence, even the goddess Juno must submit to fate. While some argue that Jove and fate are one and the same, scholar Woodworth argues that in asking Juno to submit to fate rather than to himself, Jove is actually showing that fate stands outside of even his own abilities--all are ruled by fate. We particularly see Jove referring to fate as being something outside of himself in his lines:
What new arrest, O Queen of Heav'n, is sent
To sotp the Fates now lab'ring in th'event?
What farther hopes are left thee to pursue? (Book XII)
The exact opposite is actually true of Homer's gods. In the Iliad, all of the gods control actions thereby directing fate; they do not necessarily submit to fate.
Homer actually took a liberty with his gods. He characterized them in such a way as to underline his themes in the Iliad. The Iliad's most important themes concern the consequences of dishonorable behavior, such as how Achilles is mistreated by Agamemnon, and the consequences of vengeful anger, such as the anger Achilles held on to due to Agamemnon's behavior that nearly killed the entire Greek army. Just like the human beings, the gods also have their own petty desires to be spiteful and vengeful, as well as desires to manipulate things, causing either suffering and failure or happiness and success accordingly. Hence, unlike Virgil's gods, Homer's gods have many more human characteristics, such as the ability to have human emotions and to have both "virtues and vices" ("Iliad: Gods"). But the greatest distinction between Homer's and Virgil's gods is the gods' ability to control destiny, to control what happens and does not happen. In the Iliad, the gods' interventions have a direct impact in the outcome of events. For example, it can be said that Troy would not have been defeated had Hera not been successful in persuading Zeus to allow it to happen, as we see in Book 4 ("The Gods in the Iliad").
However, what is also true of the gods in both books is that all of the gods have the ability to manipulate human actions. We see one example of this when Venus tricks Dido into falling in love with Aeneas and then Juno tricks Dido into falsely believing she is married to Aeneas due to their consummation, which is also Juno's attempt to prevent Aeneas from leaving Carthage, which would also prevent the establishment of Rome. However, Juno's trick is ultimately unsuccessful, showing again that the gods in the Aeneid must submit to fate. Hence, the gods evolved in Virgil's Aeneid from Homer's Iliad from being able to manipulate fate as well as humans to having to submit to fate.