Probably by Bartolomeo Caporali, 'Saint John the Baptist', probably 1475-80

Two of the most popular late medieval saints – Francis, who died in 1226, and Bernardino of Siena, who died in 1444 – present a young man to the Virgin and Child and a choir of angels: he is the altarpiece’s patron. In the outer panels stand Saints John the Baptist and Bartholomew.

This kind of altarpiece – a triptych with a larger panel in the centre, flanked by standing saints traditionally set against a burnished gold ground – was the most popular form in Italy through much of the Middle Ages. Large churches would have had multiple altars, each with its altarpiece; even quite small parish churches may have had several.

We don‘t know exactly where this altarpiece came from, though Bartolomeo Caporali seems to have worked mainly in Umbria. We don’t know the patron’s identity, though he was clearly a man with a special devotion to the Franciscans, friars who took religious vows but were not confined to a monastery. Founded in the thirteenth century to provide educated preachers and teachers for a growing urban population, they flourished in fifteenth-century Italy. Men who joined the Franciscan Order took vows of poverty and travelled from place to place, preaching and living on what was given by their listeners.

This is one of the few paintings of saints that actually resembles the person it depicts. Bernardino was a famous mendicant preacher and drew large crowds to his outdoor sermons. He spoke out against ‘vices’ such as fine clothing and homosexuality, and encouraged a devotion to the holy name of Jesus; he is often shown with an IHS monogram, as in Giorgio Schiavone’s painting of him. He wears the ash-grey habit of the especially strict Observant (reformed) Franciscans, known in England as the Grey Friars. Many paintings were made of Bernardino immediately after his death – possibly from his death mask (which still survives) – and show him as here: an old man with a toothless mouth and sunken cheeks.

Caporali was born, died and worked in Perugia and his very traditional style – the smooth, flowing lines, decorative colours and burnished gold backgrounds hark back to International Gothic – was primarily influenced by the work of his teacher Benedetto Bonfigli. Some aspects recall Florentine painting: the radiating lines incised into the haloes are derived from Florentine painters of the 1430s and 1440s, such as Fra Angelico and Fra Filippo Lippi. The smoothness of his paint handing – look at the skin of the Virgin and the angels – and his way of painting draperies show similarities with Benozzo Gozzoli.

All the panels in this altarpiece have been cut down. The marble parapet would have run horizontally across all three panels, and they had pointed arched tops. The original frame, which was possibly very elaborate, is also missing. There might well have been more panels and possibly a predella.