Laudator Temporis Acti

Simone Martini, frontispiece to Petrarch's manuscript of Vergil (Milan, Biblioteca Ambrosiana, MS S.P. 10, 27, formerly A 49 inf.):


Danielle Joyner, in Jan M. Ziolkowski and Michael C.J. Putnam, edd., The Virgilian Tradition: The First Fifteen Hundred Years (New Haven: Yale University Press, 2008), pp. 452-453:

In the upper right corner of the image, Virgil reclines against a tree and props an open book in his lap. Represented as a bearded older man wearing long white robes and crowned with a laurel wreath, he lifts a feather pen and tilts his head back to gaze up into the sky, caught in a moment of contemplative reverie before writing the inspired words. Servius (see below, IV.B) reveals him to the reader not only by his commentary, which is included in the manuscript, but also by his action of drawing aside a checked curtain that hangs from a rod painted across the entire image. A soldier or knight with a sheathed knife on his belt and a long spear in his right hand stands behind Servius. Below them to the left, a farmer prunes a small orchard of trees, and in the center a shepherd milks one of four sheep. The curtain rod and plaid curtain are not the only artificial notes in this otherwise Edenic landscape; two scrolls unfurled and held open by a pair of red- and blue-winged hands are painted below Virgil. The couplets inscribed on each scroll and a third verse in the lower margin are identified as written by the hand of Petrarch himself.

The first couplet reads:

Itala praeclaros tellus alis alma poetas
Sed tibi Graecorum dedit hic attingere metas.

Italy, dear land, you nurture the famous poets,
But this man has enabled you to attain the eminence of the Greeks.

A certain amount of nationalistic pride blends with a pastoral reference to the land as nourishment for the poet, a verbal parallel to Martini's lush landscape of trees and flowering fields.

The second couplet reads:

Servius altiloqui retegens archana Maronis
Ut pateant ducibus pastoribus atque colonis.

Servius unveiling the secrets of Virgil the eloquent,
So that they may be plain to knights, shepherds, and farmers.

This reference to knights, shepherds, and farmers has been interpreted in several ways: as the three social groups for whom Servius wrote, the three allegorical stages of Virgil's life, the three levels of poetry written by Virgil, or even as the three rhetorical styles exemplified in the language of the Eclogues (shepherd), Georgics (farmer), and Aeneid (knight) as diagrammed by John of Garland’s "Virgilian Wheel" (see below, IV.S). (Discussion: A. Martindale, Simone Martini [Oxford, 1988]; M.L. Lord, "Petrarch and Vergil's First Eclogue: The Codex Ambrosianus," Harvard Studies in Classical Philology 86 [1982], 253–76; J. Brink, "Simone Martini, Francesco Petrarca and the Humanistic Program of the Vergil Frontispiece," Mediaevalia 3 [1977], 83–117; C.J. Campbell, "'Symoni nostro senensi nuper iocundissima.' The Court Artist: Heart, Mind, and Hand," in Artists at Court: Image-making and Identity, 1300–1550, ed. S.J. Campbell, Fenway Court 31 [Boston, 2004], 33–45)

Eric Thomson writes:

The trees are surely more than just pastoral props for the curtain rail. Isn't the central tree a kind of visual prolepsis, the cross of Golgotha partially veiled as symbolic of the partial revelation bestowed on Vergil? If so, you have a neat triangle formed by Christ the Vine on the left and Lamb of God on the right. It would be surprising if there weren't a Christian triad to superimpose on the others.

I dare say say it's all in the bibliography. Even so it's always satisfying to arrive unaided at a destination even if it seems the glaringly obvious one to others.