Pietro Testa was an Italian draughtsman, printmaker and painter, born in Lucca, who spent most of his career in Rome where he moved in 1628-30. Here he trained with Domenichino and Pietro da Cortona. Testa then worked for Cassiano dal Pozzo, Nicolas Poussin's patron, making several hundred copies of sculpture and classical remains for his Museum Chartaceum (paper museum). He was not very successful as a painter and spent much of his life in poverty, but he was recognised as a talented etcher and draughtsman. He returned to Lucca in 1632 and again in 1637, looking for work in his home town. Following his return to Rome in 1638, he obtained a number of public commissions for paintings, but his frescoes for S. Maria dell'Anima in Rome were not well received and, around 1647, his designs for decorating the apse of S. Martino ai Monti in Rome were rejected. He became increasingly despondent and died by drowning in the Tiber, probably suicide, in 1650. The Royal Collection holds a substantial number of works by Testa.

This miniature is one of the collection of copies of 224 self-portraits by artists in the Uffizi Palace, Florence, that Lord Cowper, the art collector and patron, commissioned Giuseppe Macpherson (1726-1780) to paint. He presented the miniatures to King George III in two batches, in 1773 and 1786. Macpherson followed the original self-portraits quite closely, but copied only the head and shoulders. He inscribed the artists' names on the backs of the miniatures – several differ from those in the modern Uffizi catalogue, notably: Bazzi, Bellini, Campi, Annibale Carracci, Gabbiani, Masaccio, Metsys, Moroni, Pencz, Licinio, Schiavone and Spada. None of the miniatures is signed, apart from Macpherson's own self-portrait, which is inscribed: Giuseppe Macpherson / Autore della serie (Giuseppe Macpherson / Author of the series).Macpherson was born in Florence, the son of Donald Macpherson, a footman in the service of Alexander, 2nd Duke of Gordon. He was a pupil of Pompeo Batoni and painted miniatures and enamel portraits in Italy, France and Germany, finally settling in Florence. A James Macpherson is recorded in London and Paris in 1754 but it is not certain that this is the same person. He was described in 1776 as having a special talent for painting on enamel and as being 'almost the only painter in Europe who possesses this art to perfection'. He had a distinguished client list which included some of the crowned heads and dignitaries of Europe. In 1778, he was invited to add his own self-portrait to the famous painters in the grand duke's collection as it 'would do honour to Florence to enrich the collection with a work which shows that we still have some men of true merit' according to Giuseppe Pelli, director of the Uffizi at the time.