Madonna and Child with the Young Saint John

This is early Correggio, painted in Parma around 1516 while he was still teaching himself from the great names of the generation before him. He set the Virgin and the two children in a rocky cavern with softly blurred edges and precisely observed plants, and the source is unmistakable. It is a free reworking of Leonardo da Vinci's Virgin of the Rocks, down to the sfumato haze and the botanical exactness. The Virgin's classical sandals, by contrast, come from Mantegna, who had worked nearby. So the panel is a young painter openly borrowing from two masters at once and folding them into something of his own. It reached Madrid two centuries later with Isabella Farnese, the Parma-born queen of Spain, who brought a great deal of her homeland's art to her new court.