Ovid announces in the proem of his epic (Met. 1.1-4) a change of meter, from the elegiac couplets of his previous poetry to epic hexameters, and of inspiration, from Cupid to the whole divine pantheon; and he comments on his innovation in the opening words, in noua fert animus (Met. 1.1), which can be read autonomously to mean ‘my inspiration bears [me] on to new things’. The novelty of the poem’s subject-matter is complemented by the poet’s new excursion into hexameter verse, a metrical innovation underscored in the second line’s parenthetical comment crediting the gods with transforming not only the changed forms which constitute the poem’s subject matter, but also Ovid’s verse form itself, since they have metamorphosed his poetry from elegiac verse into epic. The metaliterary comment revisits and reverses the opening scene of Ovid’s earlier Amores, where the god Cupid steals a foot from the second line of his projected epic and thereby sets him on an elegiac course (Amores 1.1.1-4).

Ovid’s decision to compose the Metamorphoses in dactylic hexameters, the meter of classical epic, has often been explained as arising from ‘the impulse of the Aeneid’, and the influence of Vergil is everywhere apparent in the poem, from the renovation of Vergilian diction and metrical techniques to the appropriation of Vergilian themes (e.g., city-foundation and familial piety) and subjects, including the fall of Troy and Aeneas’ wanderings in the Mediterranean in  a mini-‘Aeneid’ (Met. 13.623-14.608). Yet while Vergil may have been the most immediate spur to Ovid’s epic production, the whole of the classical epic tradition informs his essay in hexameter poetry. Ovid mines Homer as well as Vergil for myths of metamorphosis, making their epics prototypes for his new poem. Thus, the proem draws on the language of Homeric and Vergilian heroic epic to announce a theme characteristic of didactic rather than martial epic. The phrase mutatas formas (‘changed shapes’, Met. 1.1), by which title Ovid also refers to the Metamorphoses in the exile poetry, does double duty in this regard, for while it can be read as alluding to Homer’s Odysseus, a man ‘of many turns’ (polytropon, Od. 1.1), it more obviously puns on the theme of the Hellenistic Greek poet Nicander’s didactic (catalog) epic Theriaca, which catalogs the ‘shapes and wounds’ of snakes; and the latter poet’s Heteroioumena (‘Transformations’), a catalog epic no longer extant, was also undoubtedly an important model for Ovid in the Metamorphoses, though its loss makes it impossible for us to assess Nicandrian influence in detail.

Another important model for Ovid’s fifteen-book hexameter poem was furnished by Rome’s first hexameter epicist, Quintus Ennius (239-169 BCE), whose eighteen (originally fifteen) books of Annales charted Roman (i.e., universal) history from the Fall of Troy through the foundation of Rome and the regal period down to the republican era, including events from his own lifetime. Ovid broadens Ennius’ (already sweeping) temporal perspective to write a university history ‘from the first origin of the world down to my own times’ (Met. 1.3-4). The Metamorphoses accomplishes this ambitious program by opening with Chaos (1.5-7) and concluding with an epilogue (15.871-8) that links its author’s immortality to his poetic monument. By invoking not only Homer and Vergil, but also Nicander and Ennius, so prominently in the proem, Ovid signals that the Metamorphoses will combine the traditions of heroic and didactic epic in a comprehensive culmination of the genre.

Ovid implicitly confirms the generic classification of the Metamorphoses as epic by opening the poem proper with a cosmogony (1.5-88), a philosophical subject traditionally considered the most elevated poetic theme and therefore the subject best suited to the most elevated poetic genre, grand epic. The subjects that succeed the cosmogony down to the flood narrative in the first half of the book also exemplify the conventional themes of high epic. Similarly extensive panels of grand epic subjects composed in the grand epic manner open books 2 (Phaethon’s ride in the chariot of the Sun), 3 (Cadmus’ foundation of Thebes), and 5 (Perseus’ defense of his bride Andromeda, first from a sea-monster and then from her uncle’s siege), and recur throughout the poem, for example in books 8 (the Calydonian boar hut), 10 (Orpheus’ katabasis), and 13-14 (Ovid’s ‘Aeneid’).

The implied rejection of elegy for epic at the outset of the Metamorphoses is complicated by Ovid’s decision to bring his poem down to his own ‘times’ (tempora, Met. 1.4), a progression that undoubtedly recalls Ennius’ epic Annales, but also leads the reader back to Ovid’s own elegiac Fasti, composed contemporaneously with the Metamorphoses, and whose first word ‘Times’ (tempora, F. 1.1) functions, by ancient literary convention, as an alternative title. Both contemporary works thus grapple with the problem of time, from the complementary perspectives of cyclical, religious, elegiac time in the Fasti and linear, historical, epic time in the Metamorphoses. Moreover, just as the Fasti broaches epic themes in elegiacs, so the Metamorphoses flirts with elegiac themes in its hexameters. For example, in the final line of the proem (Met. 1.4) Ovid adapts the Hellenistic Greek poet Callimachus’ elegiac language of literary program to characterize his own innovative hexameter poem as both ‘continuous’ (i.e., epic) and ‘fine-spun’ (i.e., elegiac). Midway through the first book, moreover, he introduces the ‘first’ of many ‘love’ stories into his Metamorphoses (primus amor, 1.452), when Cupid deflates the arrogance of Apollo, in the aftermath of his defeat of the monstrous Python, by shooting him with one of his own arrows and inspiring in him an unrequited love of the virginal Daphne (1.465-74), transforming the divine archer into an elegiac lover. Ovid embeds the narrative of Apollo’s erotic pursuit of Daphne in an etiological framework – describing the foundation of the Pythian games and origin of Apollo’s association with the laurel – that further contributes to the elegiac tenor of the episode, since it gestures toward Callimachus’ elegiac Aetia as a model.

Nor is elegy the only genre with which Ovid flirts in the Metamorphoses. The speeches of a series of impassioned mythological heroines in the central books (Philomela and Procne in 6, Medea in 7, Althaea in 8, Myrrha in 10, Hecuba in 13) take their bearings from the tragic monologues of ancient drama, while the rhetorical contest between Ajax and Ulysses for the arms of Achilles at the opening of 13 draws heavily on the conventions of classical rhetoric and courtroom oratory. Ovid even draws on his own innovative elegiac epistles in the love letter Byblis writes in book 9 to her brother Caunus. Throughout the Metamorphoses, in fact, Ovid adapts a comprehensive array of textual sources and literary genres on a scale that ranges from pervasive engagement with the conventions of epic, epyllion, elegy, tragedy, and rhetoric all the way down to highly localized use of modes philosophical, religious, hymnic, funerary, legal, oracular, annalistic, historical, and novelistic. As universal history, the Metamorphoses is also universal literary history.

The transformation of such a wide variety of sources contributes to the larger metamorphic project the poem represents. Ovid includes over 250 myths in the poem, most (but not all) containing a metamorphosis, some central to the story, others incidental. Human transformations into gods (apotheoses), animals, plants, and features of land, sea, and sky (catasterisms) offer etiologies for a wide array of natural and cultural phenomena and populate the poem with new and, paradoxically, enduring forms. Divine transformations, however, are reversible: thus Jupiter, who presides in book 1 over an epic Council of the Gods, assumes in book 2 the form first of the goddess Diana (to rape Callisto) and then of a bull (to rape Europa), while in book 3 he appears to Semele as a thunderbolt. As this sketch of Jupiter’s activities early in the poem implies, the Ovidian gods do not necessarily act from lofty motives: ‘majesty and love are not well suited nor stay long in the same place’ (2.846-7), Ovid says of Jupiter’s transformation into a bull. The subjects of Arachne’s tapestry (a series of divine rapes, 6.103-28) bear witness to the gods’ caprice, as does her transformation into a spider at Minerva’s hands; by contrast, Minerva’s tapestry (her contest with Neptune for patronage of Athens, 6.70-102) self-servingly testifies to divine justice (theodicy) and authority. Human metamorphoses in the poem occur not only in punishment (e.g., Juno’s transformation of Callisto into a bear) but also in reward (e.g., Jupiter’s transformation of the bear-Callisto into the constellation ursa maior), as Ovid repeatedly explores the problematic disjunction between divine justice and divine authority.

Ovid’s transitions from one tale to the next can seem contrived, though as Quintilian observed (Institutes of Oratory 4.1.77), ‘the requirement of connecting the most diverse matters into the appearance of a single form can excuse’ the affectation. A favorite technique is to set stories in the mouths of characters, often in response to an event (e.g., Achilles’ defeat of the invincible Cycnus at Troy, which prompts Nestor’s tale of the invincible Cauneus [née Caunis] in the Battle of Centaurs and Lapiths in book 12) or in storytelling contexts (e.g., the Minyads in 4). Such ‘embedded’ narratives both enliven the mythical tales Ovid includes in his poem and multiply their number, while also allowing him to reflect self-consciously on his own artistry through the mise-en-abŷme structure of story-within-a-story. The poem’s primary narrator, often identified with Ovid though he nowhere signs his epic, intervenes freely in his own narration, prefacing it with a proem and concluding it with an epilogue anticipating his poetic immortality; but, as in Heroides and Fasti, he also cedes narrative authority to his characters, sometimes multiplying such internal narrators to dizzying effect. In book 5, for example, an unnamed Muse in conversation with Minerva reports her sister Calliope’s winning entry in a singing contest between the Muses and Pierides, and she includes within Calliope’s song the nymph Arethusa’s account of her own transformation into a Sicilian fountain. Sustained panels of embedded narrative structure the poem into five-book triads, with Calliope’s song occupying the bulk of 5, Orpheus’ song of 10, and Pythagoras’ discourse of 15. The resulting dialogism constitutes another metamorphic strand in the poem’s sustained and witty exploration of the nature and meaning of transformation.

In 8 CE, the fifty-year old poet was putting the finishing touches to his masterpiece, and had long been the most famous living Latin poet, when he witnessed something prejudicial to the emperor Augustus, who summoned him to account. Subjecting Ovid to no public proceedings, the emperor personally tried him and delivered sentence, relegating him from Italy by a specific date, and requiring him to take up residence in Tomis (modern Costanza in Romania) on the Black Sea. With an eye on the tale of Vergil’s death-bed desire to burn the Aeneid, Ovid claims that before his departure from Rome he burned the Metamorphoses, a work which his exile ‘broke off’, but copies already in circulation saved the poem for posterity. Ovid himself bears witness to the early popularity of his Metamorphoses in this anecdote, and the elder Seneca, writing a decade after Ovid’s death, confirms the fame of the epic. Already discernible in the elder Seneca is the bifurcated reception of Ovid’s work, enthusiastic among writers and artists, who give evidence of their admiration by frequent citation and repeated reworking in imperial Latin literature and art, but censorious among critics, who denounce his poetry for moral laxity and poetic license. In the century following Ovid’s death, his epic is second only to Vergil’s in its impact on writers’ selection and treatment of themes and, indeed, more influential than Vergil’s in the dominance of his hexameter metrical technique. Even more significant is Ovid’s influence among artists, if the extensive repertoire of Ovidian subjects in Pompeian painting and imperial sculpture is representative. In the second century CE, moreover, the imperial biographer Suetonius (c. 69-after 122 CE) and the Greek satirist and rhetorician Lucian (c. 125-180 CE) report a number of fashionable dance-themes that imply the wide popular diffusion of Ovid’s amatory and mythological subjects in the contemporary performance culture of mime and pantomime.​