A Prague festival will host the world premiere of Antonio Vivaldi’s opera L’Unione della Pace, e di Marte, following its reconstruction by a Czech expert 284 years after its only performance.

“It’s a specific genre of baroque opera, shorter, which is called la serenata and which was composed for a specific occasion at that time,” conductor, composer and harpsichord player Ondrej Macek said.

Vivaldi (1678-1741) composed the serenata L’Union della Pace, e di Marte (Union of Peace with Mars) for the birth of French King Louis XV’s first children, twin sisters Louise Elisabeth and Anne Henriette.

“Ordered by the French ambassador to Venice, the work was performed only once, in mid-September 1727, in the open air, in a garden adjacent to the church of Madonna dell’Orto in Venice,” said Mr Macek.

The complete libretto, containing notes on the birth of the twins in August 1727, and on the political situation of that time, has been preserved in the National Braidense Library in Milan.

But the score disappeared altogether, and had to be reconstructed on the basis of tunes from Vivaldi’s other operas.

“When I was reading the libretto for the first time, I could already see that many songs look familiar to me,” said Mr Macek, who in 2008 discovered and then reconstructed a major part of Vivaldi’s lost opera Argippo which had premiered in Prague in 1730.

“As the composer did not have too much time to create this serenata for that sole performance, he logically used themes from his other operas,” he added.

“At that time, it was a usual and legitimate method of composition, especially in Italy,” said the 39-year-old expert on baroque music.

The international ensemble Hof-Musici, led by Mr Macek himself, will perform L’Unione della Pace, e di Marte several times within the Prague Baroque Festival starting on June 17. The premiere is scheduled for July 4.