Justus of Ghent and workshop, 'Rhetoric', probably 1470s

These large panels are the sole survivors of what must have been one of the most ambitious schemes of interior decoration of the period. They came from a series showing the seven liberal arts, which formed the core of medieval learning: the trivium of Dialectic (logic), Rhetoric (argument) and Grammar (language); and the quadrivium of Arithmetic, Geometry, Music and Astronomy. Two other paintings from the same series were in Berlin, but they were destroyed in 1945. One of National Gallery’s paintings clearly shows Music with her attribute of an organ and the other has generally been identified as Rhetoric. One of the Berlin paintings showed Astronomy with an armillary sphere, while the woman in the second is usually called Dialectic.

The Liberal Arts were frequently represented as enthroned women, often accompanied by exponents of their arts seated below or beside them. In the Berlin panel of Grammar, the kneeling man is Federico, Duke of Urbino, one of the most important condottiere (captains of mercenary soldiers) of the day, and renowned for his military skill and his love of arts and literature. The four allegories are related in style to the portraits of Famous Men made for the studiolo (study) of Federico’s palace at Urbino. All were probably painted by Justus of Ghent, who was working in Urbino by 1473. According to his biographer, Federico had excellent understanding of painting but couldn‘t find anyone in Italy who knew how to paint in oil. He sent to Flanders and found ’an eminent master‘ to come to Urbino, and had him paint many panels.

We aren’t sure exactly where the London and Berlin paintings were originally displayed. All were cut down from very large and heavy panels which showed more than one of the liberal arts. They were clearly made for a specific setting, perhaps Federico’s palace at Urbania in the Marche. The inscriptions on the frieze at the top give some of Federico’s titles, and the words ‘DURANTIS COMES’ (Count of Durante) were placed over the head of Grammar and Federico (Urbania was called Castel Durante in the fifteenth century). They might well have been in the Duke’s studiolo – images of the Muses were popular subjects for such a location.

The panels are made of poplar wood – the usual material for Italian painting – and had two rows of metal fixings inserted in the back, allowing them to be hung securely in a way that was invisible from the front. They were probably angled slightly away from the walls so that they could be seen better. They were meant to be hung high and seen from a distance, influencing how the artist painted: it is a soft style, where lines aren't sharply defined and there is no precise detail.

Netherlandish oil painting was very fashionable in Italy, and Federico was clearly a fan: fresco, the standard Italian technique for wall decoration at the period, would have been much easier and cheaper. The pictures seem to have been painted very quickly, and maybe partly by assistants. Federico, with his many building projects, was perhaps an impatient patron, and might have found it hard to understand that oil painting took longer than fresco.