The Paralipomeni della Batracomiomachia began to take shape around 1831 from an idea of Giacomo Leopardi, who managed to complete a version of it—though without fully polishing it—shortly before his death in June 1837. Like nearly all of Leopardi’s narrative works, it is marked by bursts of intense creativity, alternating with long pauses, partly due to the poet’s fragile health. In fact, it was his friend Antonio Ranieri who transcribed the final stanzas as Leopardi dictated them, unable to move but still perfectly lucid.

The title Paralipomeni comes from the Greek paraleipomena, meaning “things left out,” and in fact, the poem picks up directly where the pseudo-Homeric Batrachomyomachia leaves off. Leopardi’s passion for the ancient tale is evident from the three separate translations he produced—in 1815 (La guerra dei topi e delle rane), 1821 (Guerra de’ topi e delle rane), and 1826 (Guerra dei topi e delle rane)—likely the spark that led him to write a fictional continuation of the unfinished legendary poem.

The narrative, divided into eight cantos, begins with the hasty retreat of the mice, defeated by the frogs, who are aided by the crabs sent by Zeus to their rescue. A difficult period then begins for the mice, who find themselves without a king and constantly threatened by crabs, now clearly superior. In fact, the crabs decree that Rat City must be garrisoned by thirty thousand crabs and insist that the next king be legitimate in their eyes.

The valiant Chunk-Stealer is elected provisional leader of the mice, pending the establishment of a constitutional regime headed by Bread-Muncher, with Bottom-Licker serving as his interior minister. However, the positive economic and cultural reforms that Bottom-Licker manages to implement are frowned upon by the crabs, who immediately send their own representative, Ironed-Mouth, to oversee developments and compel Bread-Muncher to become an absolute ruler. But Ironed-Mouth is rebuffed, and war breaks out once again between the two factions.

This time, the conflict barely has a chance to ignite: as soon as the mice see their enemies, they flee, and the only casualty is Chunk-Stealer, who tragically hurls himself alone against the opposing army. The crabs’ victory is thus complete: the reactionary Crooked-Walker, installed as the new minister, begins dismantling all the laws previously enacted by Bottom-Licker, who is now forced into exile.

The final two cantos of the poem are devoted to Bottom-Licker’s adventures: they recount his encounter with Daedalus, whom he meets by chance in his palace after a storm. Daedalus—the only human character in the poem—is benevolent toward animals, having spent his life studying their “souls” and exploring their afterlife. In keeping with the structure of a classic epic poem, Bottom-Licker is then guided through the mice’s Underworld, which he reaches by a flight that allows him to view the (still prehistoric) world from above.

Once Bottom-Licker arrives in the Underworld, the dead seem to mock his vain hopes, offering only the advice that he speak with Taster, a famous general still among the living. Finally, the story concludes with Bottom-Licker’s stealthy return to the city, where he succeeds in questioning Taster—though, according to the author, no record of their conversation survives.

It is clear that Leopardi was not simply aiming to entertain with an animal fable. The continuation of the conflict among mice, frogs, and crabs becomes a playful allegory of the political contradictions of his own time. Beneath the fratricidal war between mice and frogs lies the rivalry between Italian liberals and conservatives, particularly the Papal faction, whose power in nineteenth-century Italy was enormous. The might of the crabs, meanwhile, reflects the political interference of Austria, which after 1815 had annexed part of northern Italy at the Congress of Vienna. Leopardi does not limit himself to allegory, however; he peppers the poem with explicit references to both ancient and modern figures, from the Duke of Alba Hernando Álvarez de Toledo to the philologist Barthold Georg Niebuhr. The battlefield becomes, in effect, a game board on which Leopardi mixes real and fictional characters, indulging his desire to mock his age with dazzling wit and erudition.

As in much of Leopardi’s work, philosophical themes emerge alongside satire. One of the most striking is a long digression in the fourth canto that ridicules providentialist views of history. According to Leopardi, all living beings—whether crabs, mice, or men—like to believe the world was made for them and that their destiny is watched over by a benevolent Nature: “It is assumed for certain that Nature is always concerned with the well-being of the animals, that she loves them heartily as the good mother hen does with the chick she has under her wings” (IV, 11). But this illusion, born partly of the instinct for peace of mind, collapses against the facts: “All of their species came into the world civilized, each one according to its natural degree, and all of them, through their own fault, fell to the bottom from such a fortunate state, and now they are wretched. And heaven, which had provided well for their needs, has no fault in their miserable state” (IV, 23).

The mythical world Leopardi builds, inhabited almost exclusively by ancient animals locked in endless warfare, grows ever more human and real. He refuses the easy temptation of idealizing the past with tales of noble heroes and great ideals (laudatio temporis acti). Instead, envy, suspicion, and vanity dominate these small societies, which cannot achieve peace. War becomes the inevitable outcome, sending waves of mice into the Underworld, indifferent at last to life itself.

Leopardi turns the perspective upside down: it is not that mice possess human dignity, but rather that humans should recognize how little they differ from beasts. This bitter conclusion reflects his resentment toward an age he found unworthy, unjust, and deceitful. And if men refuse to listen to reason—then better to speak of mice.