Lalli was born and raised in Naples as the adopted son of Fulvio Caracciolo but fled the city after being implicated in a bank fraud.
After two years wandering about Italy in the company of Emanuele d'Astorga, he settled in Venice in 1710 and worked as the "house poet" of the Grimani family's theatres for the rest of his career.
Modern accounts of Lalli's life prior to arriving in Venice are largely based on a biography included in a book of poetry which he published in 1732.
[3] A further biography of Lalli by Andrea Mazzarella[b] was published in 1818 in Biografia degli uomini illustri del Regno di Napoli.
At the age of 11 months, he was adopted by Fulvio Caracciolo, a member of a Neapolitan noble family and the second son of the Duke of Martina.
[9] There he befriended Emanuele d'Astorga, a composer and son of a Sicilian aristocrat, who used Biancardi's poems as texts for several of his cantatas and serenatas.
Left destitute after they were robbed by their servant in Genoa, they managed to scrape together some money when d'Astorga set a libretto for an impresario of the opera house there.
Zeno recognized the poems which had been published several years earlier in Naples and said that while the poetry had merit, Lalli was either a plagiarist or was actually Sebastiano Biancardi.
According to Strohm, he proved particularly useful in obtaining the latest libretti written by Metastasio for Rome, slightly revising them and having them set by another composer for a rival production in Venice.
However, a setting by Nicola Porpora of the slightly altered libretto had premiered at the Teatro San Giovanni Grisostomo a month earlier.
[12] Lalli's first original opera libretto, L'amor tirannico ("Tyrannical Love") was performed with music by Francesco Gasparini in 1710 at the Teatro San Cassiano in Venice.
Writing in 1811, Pietro Napoli-Signorelli[f] described Tigrane, the first libretto Lalli wrote for Scarlatti, as "full of oddities and fantasy" and displaying "great inventiveness in its design".
In 1723, in addition to his work for the Venetian theatres, Lalli became the court poet for Maximilian Emanuel, Elector of Bavaria and later his son Carl Albert.
Goldoni's contemporary, Gasparo Gozzi, lamented that Lalli's financial predicament was commonplace for those working in the arts in 18th-century Venice and described him as a man "who was born rich and died a poet".
[3] The restoration of the Bourbon king Charles VII to the throne of Naples in 1735, raised Lalli's hopes of being able to return to his native city.
In 1738 he wrote the libretto for Partenope nell'Adria, a serenata composed by Ignazio Fiorillo celebrating the marriage of Charles to Maria Amalia of Saxony and described himself on the title page as the King's "fedelissimo vassallo" ("most faithful vassal").