Boltraffio began his career in the studio of Leonardo de Vinci in Milan, where he was the Master’s chief pupil. You can tell at once that he worked in Leonardo’ studio: the subtle modelling of the forms with delicate shadows – sfumato, or ‘smoked’ – is typical of Leonardo’s manner, a determination to present objects, especially the human figure, as three-dimensional in a luminous space. The whole group projects itself towards us with an almost hallucinatory clarity and vividness.

Another characteristically Leonardesque element in this arresting painting is the energetic movement of the figures. We come across this feature often enough in the master’s output, but it is extraordinary for its time. It was something that an artist in three plastic dimensions, a sculptor – Michelangelo – could develop naturally enough, but the painters of altarpieces still mostly adhered to the more formal arrangement of figures in poised symmetry. The supreme master of this symmetry was Raphael, another giant of the period, but Raphael too sometimes, late in his career (he died in 1520) explored more intricate interrelations between the figures of a Holy Family.

Boltraffio himself made a Madonna and Child more obviously symmetrical and stable in composition. It is in the National Gallery in London: a calm, frontally posed Virgin, seated before an embroidered hanging panel, with the child lying almost horizontal, at her breast. She has the calm meditative expression that combines maternal love and religious contemplation, that serene beauty the Italian masters knew so well how to evoke. In the Budapest picture she has the same expression – a typical Leonardo half-smile – but her head is tilted towards the Child and her meditative gaze is away from him, perhaps focusing on something inward, but perhaps sharing the Child’s fascination with an object or event outside the picture. What is the Child reaching for so eagerly? His eyes don’t seem to share the excitement expressed by his twisting body; they are not directed at the beautifully decorated pot in the left corner: they are glazed, as though hypnotised. He is reaching almost blindly for something beyond the frame of the picture – perhaps for the source of the light itself that illuminates both Mother and Son.

Both appear absorbed in another world, another place: and the light, the energy that inspires them is as much a personality of the drama as they are themselves. This is a Holy Family in which God the Father is present as an unseen but vital force, close at hand, and understood by each of the figures we can see in their own distinctive ways.