Giovanni Francesco Barbieri, called Guercino (Squinter) (1591-1666), was an Italian painter and draughtsman born in Cento, near Bologna. In 1621, his patron Cardinal Alessandro Ludovisi was elected Pope Gregory XV and Guercino was summoned to Rome. Among other commissions there he painted the celebrated ceiling fresco of Aurora (1621) in the Casino of the Villa Ludovisi. He returned to Cento when the pope died in 1623. He had many international patrons, including King Charles I who tried to persuade him to come to England. According to Carlo Cesare Malvasia, his biographer, Guercino declined because the country was heretical and the weather terrible. In 1542, after the death of Guido Reni, Guercino moved to Bologna, but he suffered from ill health in his later years and depended ever increasingly on his workshop assistants, particularly his nephews Cesare and Benedetto Gennari. There are several paintings and about 400 drawings by Guercino (and many more by his workshop) in the Royal Collection.

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.