“Flesh is the reason why oil paint was invented”: Willem de Kooning. If one strand in art has remained constant between the Renaissance and now, it is the enduring fascination with the portrait of an individual made in oils.

Neither revolutions in technology nor in thought (photography, Marxism) ever suppressed its appeal. Indeed, the more human individuality is threatened – by biogenetics, global capitalism, the identikit personae of YouTube – the more intensely we turn to painted portraits. Is it an accident that the National Gallery chose to launch Renaissance Faces, co-organised with the Prado Madrid and the most ambitious historical exhibition on the subject, during Frieze week? As if in answer to Regent’s Park’s frenzy of buying and selling, every work in this contemplative, scholarly show speaks of the long view, of art versus mortality, of memory and belonging as bedrocks of human existence. Yet Renaissance Faces is also about the themes that make Frieze irresistible: celebrity and power, democratisation of image-making, art as propaganda for a court or a culture.