Crucifixion Diptych (van der Weyden) and theorized that the diptych represented two panels of a four-panel work – either the two-panelled left shutter of an altarpiece, or its center two panels. Based on pictorial style, Tucker argued that the large size of the human figures relative to the size of the panels was more in keeping with figures on the shutters of "carved" altarpieces than painted ones. He also noted that the shutters of carved altarpieces tend to de-emphasize the deep perspective commonly seen in painted altarpieces, which was consistent with the shallow pictorial space of the diptych. The diptych's figures are almost two-thirds life
Saint Peter Martyr Altarpiece testimony) also mention a second altarpiece by the artist in the same church, also dating to 1476, now known as the "Saint Peter Martyr Altarpiece"'. It is therefore theorised that the altarpieces were both dismantled during rebuilding of the church in 1776, then sold to the antiquarian Grossi who sold all the panels separately and grouped some of them into the altarpiece that Cardinal Zelada bought from him. Federico Zeri and Rodolfo Pallucchini then joined the altarpieces together, initially referring to the first (the high altarpiece), the "Pietà" in the Metropolitan Museum, and then to the "Madonna" in the Museum