Preparations for the Fireworks and Festival in Piazza Navona, Rome, for the Birth of the Dauphin (30 November 1729)

On 4 September 1729 Queen Marie Leszczyńska gave birth at Versailles to a boy. After three daughters Louis XV finally had an heir, and in Rome the French ambassador, Cardinal Melchior de Polignac, celebrated at his own expense with some ten days of festivities. They ended on the night of 30 November with fireworks in Piazza Navona, the long square that keeps the shape of the ancient stadium of Domitian.

Panini shows the square in the days before, while the work is still going on. The painter Pier Leone Ghezzi had designed the temporary architecture, and it already stands around Bernini's Fountain of the Four Rivers, two columns topped with statues, a pair of triumphal arches, giant vases with winged figures beside them, all made of papier-mâché and painted to look like marble. In the foreground men are still carrying beams through a crowd of priests, ladies and gentlemen who have come to watch.

Polignac presented this canvas to Louis XV and kept a second version, now in Dublin, for himself. The boy whose birth Rome was celebrating never reigned. He died in 1765, nine years before his father, and three of his sons became kings of France.