The standard demarcations of the Virgilian career are already present at, or soon after, the poet's death in 19 BC in his epitaph and in the famous lines that purport to introduce the Aeneid. The first may, or may not, be the work of Virgil:

Mantua begot me, the Calabrians snatched me away, Parthenope now possesses me. I sang of pastureland, the country, leaders.

The Eclogues, Georgics and Aeneid are denoted by the words pascua, rura and duces, pasture for animals, ploughlands and heroes, standing emblematically for pastoral, didactic and epic verse.

Servius tells us that the second passage was excised from its place as the opening hexameters of the Aeneid, but scholarly opinion largely regards it as Tiberian in date:

I am he who once tuned my song on a slender reed, and, departing from the woodland, compelled the neighbouring fields to obey the husbandman, however grasping, a work welcome to farmers: but now [I sing] of the bristling [arms] of Mars.

Here carmen, in association with gracili auena and siluis, stands for Virgil's initial masterpiece. The Georgics is an opus that has uicina arua, worked by a colonus, and agricolae for its theme. We move into the Aeneid via the phrase horrentia Martis, anticipating arma to come.