It shows the Emperor Diocletian as one of four observers in the background of the center panel, as well as Saints Jerome and Bernard of Clairvaux in the wings of the altarpiece.

[3] On the side panels two figures are shown facing inward: left, the Church Father Jerome and on the right is Bernard of Clairvaux, founder of the Cistercian Order wearing the costume of an abbot.

While these two historical figures have virtually no link with the Erasmus, subject of the central panel, "their status as scholars would have made them admired by the members of the Confraternity, which had close ties with Louvain academic circles.

"[3] The two saints in side panels are painted larger in scale, suggesting that the wings originally would have been hinged and angled inward toward the center, helping onlookers to feel embraced by, and even part of, the scene.

"[8] A painted inscription at the bottom of the center panel (a nineteenth-century addition laid onto a non-original frame[3]) runs: Opus Theodorici Bouts.

The historian Johan Huizinga called the composition "clumsy and inept" and the entire scene "dermwinderken" ("gut-wrenching"),[10] because the central panel shows how, according to legend, the intestines of Saint Erasmus were extracted from his body with the help of a windlass.

From a neat opening in his belly, a thin line of innards is extracted bloodlessly and vertically from the horizontal man, with no more strain than drawing a thread through a needle.Max Friedländer sums up the content of the panels as "relating a story, not of cruelty as such, nor of suffering and defiance, but rather of judicial equanimity and of submission.

The repulsive scene is rendered tolerable, not by the introduction of an element of passionate agitation, but by documenting it with unvarnished and sober clarity, as though it were a surgical operation.

Yet its realism is overlaid with so much supernatural detachment, is so stiffly symmetrical, so pedantically clean that it has the effect of a symbolic tableau in a medieval mystery play.

[26] Inigo Bocken points to the similarity of Diocletian's clothing with that of the figure of Nicolas Rolin in a work by Jan van Eyck now at the Louvre.

Its two side panels, hinged and enclosing both the painted central scene as well as celebrant and participants in Christian services,[3] would have added depth and breadth to the space around the ritual.

[27] Copies of figures or sections of the work exist as paintings in the Münster Landesmuseum,[8] the Henry Cabot Lodge Collection in Washington,[31] the Palazzo Ducale at Urbino, and in the Galerie Stern at Düsseldorf.