Madonna and Child with Sts Catherine and Barbara

Nobody knows who painted this. The artist is called the Master of Hoogstraeten, after an altarpiece in that Flemish town, a placeholder name art historians use when one distinct hand keeps turning up in different works but no document attaches it to a person. This panel, made in Antwerp around the start of the 1500s, was for a long time given to a famous name, Hugo van der Goes, then passed between other attributions before the scholar Max Friedländer grouped it in 1929 with the anonymous master it now carries. The composition looks back to Hans Memling: the Virgin enthroned under a canopy, with Saint Catherine, known by her wheel, and Saint Barbara to either side. The telling detail is small. Catherine holds out an apple to the Christ Child and he reaches for it, the fruit of the first sin taken up by the child whose life is meant to answer it.