proem tells us that Aeneas is subject to a fate which will determine his destination.
he pursues his mission because he knows that it is fated
Turnus and Latinus go against fate, with tragic consequences
while Jupiter ensures the fulfilment of Fate, he does sometimes gets distracted, allowing attempts which aim to divert or postpone the inevitable
when Iarbas points out Aeneas' presence in Carthage with Dido, Jupiter cares nothing for the indignation of his son, but acts swiftly to put Fate back on course
Juno is aware that Jupiter will aways have the last word, but it won't stop her from meddling
Jupiter tells her, when she wants to save Turnus, 'if what you ask is a stay of the death that is upon him and respite for a young man who must die, and if you accept that this is what I ordain, then rescue Turnus'
the flexibility of Jupiter in the men's fortune is important
without it, the characters would be like puppets, and the poem would risk being devoid of any real characterisation or drama
fate is a useful device for Virgil in his praise of Augustus
it gives him a context within which he can refer to the future and highlight events, such as the closure of the Gates of War, the doors of the Temple of Janus