 Because van der Weyden , like most of the early Netherlandish painters , was not rediscovered until the early 19th century , many of his works were wrongly attributed or dated , and major pieces such as the Berlin <unk> Altarpiece continue to emerge . Conversely , when a number of pieces considered either by van der Weyden or assistants under his supervision were cleaned in the <unk> to late 20th century , his hand or direct influence was <unk> , or in the case of the Magdalen , associated with other images whose attribution had been uncertain . 
