The transition between book six and book seven of Virgil’s Aeneid is the turning point of the poem. Crudely considered, it is the moment the Aeneid changes from a Roman Odyssey to a Roman Iliad. And Virgil marks this transition with an invocation of the muse Erato:
And now, Erato, who were the kings
And what was the state of ancient Latium
When this foreign army landed in Italy?
Help me, Goddess, your sacred poet,
Recall the prelude to the hostilities,
For I will tell of war’s horror, of pitched battle,
Heroes driven by courage to meet their doom,
Of Etruscan squadrons, and all Hesperia
Pressed into arms. A higher order of things
Opens before me; a greater work now begins.
Curiously, however, these are the 44th through 53rd lines of Aeneid book seven. Why the longish preamble?
A first pass at an answer might be as follows. Book six ends with Aeneas leaving the realm of the dead and sailing to Caieta’s harbor. From there, Aeneas must still make one last voyage to reach the Tiber, the main center of action for the remainder of the poem. That voyage must be described before the invocation of Erato is proper. Since that would make for an anticlimactic ending to book six, it functions much better as the intro to book seven.
All of that is true, but shallow. Virgil accomplishes much more in those forty-three lines than simply conveying a necessary plot point. The way he describes the voyage from Caieta’s harbor to the Tiber itself signals the conclusion of the first half of the story and the beginning of the second, in two ways.
First, before the voyage even begins, death claims one more member of Aeneas’ party: Caieta, who nursed him when he was an infant. (It is from her that Caieta’s harbor takes its name.) So far as I can recall, Caieta is the last remaining familial link between Aeneas and Troy. His wife Creüsa was lost in book two and his father Anchises in book three. There is, of course, still Iülus, but he represents the Aeneas’ future line in Latium, and is not so strictly tied to Troy. Caieta’s death thus symbolizes a complete break with Troy except as a memory. Much more than the invocation of Erato, her death declares that what follows is to be something different.
Only after she dies do they set sail for their final landing spot. One reason why this trip can be described so briefly (<40 lines) is because it conspicuously lacks drama. Virgil doesn’t hide this fact; rather, he makes sure we are aware of it:
And from those shores could also be heard
Lions roaring and snapping at their chains
Late into the night, the raging of bristled boars
And caged bears, and huge wolf-shapes howling.
All these were men whom Circe had cruelly drugged
And clad in the hides and faces of beasts.
But Neptune, to save the good Trojans
From these monstrous transformations,
Kept them from landing on those deadly shores,
Filling their sails with wind, and bearing them past
The seething shoals and out of danger. (7.19-29)
What is interesting in this episode is what does not happen: the Trojans do not land on Circe’s shores, are not turned into wild beasts. They reach the Tiber without incident. Where Caieta’s death signaled Aeneas’ break with Troy, this non-episode signals the Aeneid’s break with the Odyssey.
To see this, compare this scene to that in book three, in which Aeneas and his crew land in Sicily and pick up Achaemenides, a member of Ulysses’ crew left behind to fend for his own against the Cyclopes (see my posts here and here). One reason why that scene appears in the Aeneid is to draw a parallel between Virgil’s poem and Homer’s (and, of course, to use this parallel as a way also to highlight their differences).
By contrast, in book seven, Virgil draws attention to the fact that the opportunity for another such parallel was present, but not taken. It was not taken because it was no longer appropriate: the time had come for something new.
Only after these two severances—the breaking of Aeneas’ last living tie to Troy, and the breaking of the Aeneid/Odyssey parallel—was Virgil ready to begin his “greater work,” and to ask Erato’s aid in his task.