Crucifixion Diptych (van der Weyden) that they could be the left and center panels of a triptych, that they formed either the wings or shutters of an altarpiece, or that they were intended to decorate an organ case. The train of the Virgin's robe continues onto the right panel, which evidences that the panels were intended to lay side-by-side rather than separated (as the wings of an altarpiece would have been). Art historian E. P. Richardson proposed that they were the center panel of the lost Cambrai altarpiece (executed between 1455 and 1459), a single painting now split into two parts. Art historian Penny Howell
Ildefonso Altarpiece Ildefonso Altarpiece The Ildefonso Altarpiece is a triptych painting by Peter Paul Rubens, dating to between 1630 and 1631. It is now in the Kunsthistorisches Museum of Vienna. It is named after the central panel, which shows Saint Ildefonsus's vision of the Virgin Mary, in which she gave him a "casula". On the side panels are Isabella Clara Eugenia and Albert VII, regents of the Spanish Netherlands, with their patron saints Albert and Elisabeth of Hungary. Albert had founded the Ildefonso Brotherhood in the church of Saint Jacques-sur-Coudenberg in Brussels, to encourage loyalty to the Habsburg dynasty - the altarpiece