Pierre Subleyras

In St Peter's in Rome, the altar of Saint Basil carries a mosaic copied from a painting by Pierre Subleyras. It shows Basil saying Mass at Epiphany in the year 372, so absorbed in the liturgy that he does not notice the emperor Valens coming in with his retinue. The commission came on 13 September 1743, to a Frenchman who had by then been living in Rome for 15 years. The canvas was unveiled to great praise in 1748, mosaicists spent the next three years turning it into glass and stone, and the original now hangs in the church of Santa Maria degli Angeli.

Subleyras was born in 1699 in Saint-Gilles, a small town in Languedoc in the south of France. In 1727 he won the Royal Academy's grand prize in Paris with a picture of the brazen serpent of Moses, and the following year he left for the French Academy in Rome. He never went back to France. In Rome he became a sought-after portraitist, painting Pope Benedict XIV and the pope's secretary of state, Cardinal Silvio Valenti Gonzaga.

Worn out by work, he tried a few months in Naples to recover his health, then returned to Rome, where he died on 28 May 1749, at the age of 49.