 The paintings are in egg tempera on wooden panels, each over 3 metres long.According to the National Gallery, London, the panels were commissioned by a member of the Bartolini Salimbeni family in Florence sometime between 1435 and 1460.The paintings were much admired in the 15th century; Lorenzo de' Medici so coveted them that he purchased one and had the remaining two forcibly removed to the Palazzo Medici.