He left France in 1728, having carried off the French Academy's grand prix, which carried scholarship for study in Rome. Cardinal Valenti Gonzaga next obtained for him the order for Saint Basil & Emperor Valens (also known as the Mass of St. Basil, which was executed in mosaic for St Peter's. Another masterpiece is his painting of St. Camillo De Lellis coming to the rescue of the diseased at the hospital of the Holy Spirit.
He was a remarkably incisive portraitist, as evident from the portrait of Pope Benedict XIV or of the obese Cardinal Valenti Gonzaga. The pope himself commanded two great paintings, the "Marriage of St Catherine" and the "Ecstasy of St Camilla", which he placed in his own private apartments. Subleyras shows greater individuality in his curious genre pictures, which he produced in considerable number (Louvre).
In his illustrations of Fontaine and Boccaccio his true relation to the modern era comes out. And his drawings from nature are often admirable (see one of a man draped in a heavy cloak in the British Museum). Exhausted by overwork, Subleyras tried a change to Naples, but returned to Rome at the end of a few months to die.
Paintings at the Louvre
Don Cesare Benvenuti
L'Absolution de Théodose
L'Ermite ou Frère Luce
Les Oies du frère Philippe
Portrait présumé de Jacques-Antoine de Lironcourt
Saint Benoît ressuscite un enfant
Saint Jean d'Avila.