Master of the Pala Sforzesca, 'Saint Paul', about 1490-5

A bearded saint stands in a scalloped niche in this small painting. This is Saint Paul, the so-called Apostle to the Gentiles (non-Jews), holding his usual emblems of a book and a sword. Paul was a Jewish convert to Christianity. He was originally hostile to the new faith – he took part in the stoning of Saint Stephen – but experienced a dramatic conversion on the road to Damascus (as depicted in The Conversion of Saint Paul) and went on to be a Christian missionary.

The book represents the series of letters he wrote to the different early churches and which are part of the New Testament. The sword is the instrument of his martyrdom: he was beheaded – as was his right as a Roman citizen – during the persecution of Christians by the Nero, the Roman emperor.

Once part of a larger altarpiece, this picture was painted in Milan in the late fifteenth century. Another panel probably from the same altarpiece is now in the Pinacoteca di Brera, Milan. We don't know who the artist was but he was one of a group of painters who were influenced by Leonardo da Vinci. Named after a large altarpiece (also in the Pinacoteca di Brera) made for Ludovico el Moro, the Sforza Duke of Milan, he is known as the Master of the Pala Sforzesca. He also painted The Virgin and Child with Four Saints and Twelve Devotees, and a very similar figure of Saint Paul appears in a cycle of frescoes in the church of San Giorgio, Annone Brianza, about 40 km north of Milan.

Technical analysis has revealed a lot about how the painting was made. Infrared reflectography shows underdrawing with short overlapping strokes rather than a continuous line, perhaps the result of transferring the design from a cartoon. Both the hand and the book were enlarged during the painting stage. The blade and hilt of the sword were incised with the help of a straight edge, as was the ledge at the bottom, and incisions were made with compasses for the circles in the top corners and for the arch of the niche.

Some of the colours have changed and the picture was probably once brighter. The saint’s robe now appears brownish, but the paint beneath the varnish and overpaint is probably a warm grey. The cover of his book was perhaps bluer: it was painted with azurite pigment, applied over the red drapery.