Metastasio was born in Rome, where his father, Felice Trapassi, a native of Assisi, had taken service in the Corsican regiment of the papal forces.

On one such occasion in 1709, two men of distinction stopped to listen: Giovanni Vincenzo Gravina, famous for legal and literary erudition as well as his directorship of the Arcadian Academy, and Lorenzini, a critic of some note.

Gravina, making a business trip to Calabria, exhibited Metastasio in the literary circles of Naples, then placed him in the care of his kinsman Gregorio Caroprese at Scaléa.

At the age of twelve he translated the Iliad into octave stanzas; and two years later he composed a Senecan tragedy on a subject from Gian Giorgio Trissino's Italia liberata – Gravina's favourite epic.

He migrated to Naples, and entered the office of an eminent lawyer named Castagnola, who exercised severe control over his time and energies.

While slaving at the law, Metastasio in 1721 composed an epithalamium, and probably also his first musical serenade, Endimione (Endymion), on the occasion of the marriage of his patroness Donna Anna Francesca Ravaschieri Pinelli di Sangro (later 6th Principessa di Belmonte) to the Marchese Don Antonio Pignatelli (later His Serene Highness Prince of Belmonte).

In 1722, while Naples was under Austrian rule, the birthday of Empress Elisabeth Christine had to be celebrated with more than ordinary honours, and the viceroy asked Metastasio to compose a serenata for the occasion.

Bulgarelli persuaded the poet to give up the law, and promised to secure for him fame and independence if he would devote his talents to the musical drama.

Under her influence he wrote in rapid succession Didone abbandonata, Catone in Utica, Ezio, Alessandro nell' Indie, Semiramide riconosciuta, Siroe and Artaserse.

In September 1729 he received the offer of the post of court poet to the theatre at Vienna, succeeding Pietro Pariati, with a stipend of 3,000 florins.

Between the years 1730 and 1740 his finest dramas, Adriano in Siria, Demetrio, Issipile, Demofoonte, Olimpiade, Clemenza di Tito, Achille in Sciro, Temistocle and Attilio Regolo, were produced for the imperial theatre.

The experience gained at Naples and Rome, quickened by the excitement of his new career at Vienna, enabled him almost instinctively, and as it were by inspiration, to hit the exact mark aimed at in the opera.

The libretto Adriano in Siria was used by more than 60 other composers in the 18th and early 19th century: Antonio Caldara (1732), Giovanni Battista Pergolesi (1734), Francesco Maria Veracini (1735), Baldassare Galuppi (1740), Carl Heinrich Graun (1746), Johann Adolph Hasse (1752), Johann Christian Bach (1765), Luigi Cherubini (1782) and in Adriano in Siria (Mysliveček) from 1776.

To make up in some measure for this comparative failure, he enjoyed the intimacy of the Countess Althann [it], sister-in-law of his old patroness the Princess Belmonte Pignatelli.

All we know is that she left him her fortune after her husband's life interest in it had expired, and that Metastasio, overwhelmed with grief and remorse, immediately renounced the legacy.

From about the year 1745 onward he wrote little, though the cantatas which belong to this period, and the canzonetta Ecco quel fiero istante, which he sent to his friend Farinelli, rank among the most popular of his productions.

In 1755 the Countess Althann died, and Metastasio's social contacts were reduced to the gatherings round him in the bourgeois house of his friend Nicolo Martines, the secretary to the papal Nuncio in Vienna.

His chief dramatic situations are expressed by lyrics for two or three voices, embodying the several contending passions of the agents brought into conflict by the circumstances of the plot.