Lorenzo Costa with collaborators, The Virgin and Child with Saints

This large painting poses one of the most bewildering problems in the history of Ferrarese painting. Changes visible with the naked eye show that it was painted in more than one stage, and some art historians have argued that it was begun by one artist but finished by another, who made alterations to the figures and architecture.

The Virgin Mary and Christ Child are seated on a marble throne, which is elevated by two plinths decorated with biblical scenes. Above Mary’s head a barrel-vaulted arch is divided into square coffers, its front extensively carved and flanked by mosaics. In front stand two saints, Saint John the Baptist and probably Saint George in armour. All are painted from a very low viewpoint: the painting was clearly meant to be placed at a considerable height.

Ferrarese painters often used complex architectural settings to give some of the visual variety of the traditional polyptychs while keeping the spatial unity of the pala format. Here, in two roundels in the spandrels of the arch, the Annunciation to the Virgin is shown as if carved in white marble relief on a gold mosaic background; the same background is used for the scenes on either side of the arch. Below Mary’s feet, also in relief, the Fall is depicted. In the lower plinth, reliefs alternate with painted scenes, showing major events from Mary’s life.

This panel was the altarpiece for the oratory of the confraternity of the Immaculate Conception of the Virgin, built between 1498 and 1500 above the refectory of the convent of S. Francesco in Ferrara. It formed the centre of a complex ensemble of panel paintings, frescoes and painted statues on the east wall of the oratory. In spite of the altarpiece’s traditional name, there is almost no evidence of any association with the Strozzi family: the patron was doubtless the confraternity.

Technical analysis clarifies the extent of the alterations. The Virgin’s head was initially more upright, and the first version of her cloak was almost entirely repainted, with many changes made to its folds and contours; the yellow lining, for example, was not part of the original design. Her left hand was altered, as was Christ’s arm, to bring his hand closer to hers, with his thumb over her finger. The cloak of the armoured saint did not originally hang from his left shoulder (you can see the architecture and chain mail painted behind it); John the Baptist’s cloak was a different colour, and was tied further to the right, on the other side of the cross. His camel skin, hanging down to the left of his legs, was lengthened and he was first shown holding a smaller, open book.

More radically, pairs of cherubic heads once seemed to float in the air around the Virgin (two level with her elbow, two level with her shoulders and a third pair possibly looking down from above her head). Technical analysis has not shown anything other than heads; if they had wings or clouds, these were painted in pigments that do not show up in X-radiographs. It’s not clear if the vault was present when the cherubs were painted, but the sky and the red curtains were certainly part of the second stage of painting. The areas behind the saints were also simplified: the stone pilasters supporting the cross-beams were initially wider, and the wall to the right was gilded to look like mosaic.

The extent of these changes have led art historians to propose that the altarpiece was begun by Lorenzo Costa and completed by Pellegrino Munari, or begun by Franceso Maineri and revised by Costa. But while the extent of the changes is surprising, they don't necessarily mean that different artists were involved. Costa was especially partial to complex architectural ensembles with subordinate narratives and liked stone reliefs against a gold mosaic ground. It’s now thought that the painting was mainly by him, possibly with two or three other artists working on the lesser narratives. Costa’s artistic ideals underwent a radical transformation around the time this altarpiece was painted, and the simplification of the setting and redesign of the drapery reflect the pictorial style of his later years.