Winged altarpiece Winged altarpiece A winged altarpiece (also "folding altar") or winged retable is a special form of altarpiece (reredos, occasionally retable), common in Central Europe, in which the fixed shrine or "corpus" can be enclosed by two (triptych), four (pentaptych) or more (polyptych) movable wings. The technical terms are derived from : "trís" or "triple"; πέντε: "pénte" or "five"; πολύς: "polýs" or "many"; and πτυχή: "ptychē" or "fold, layer". Because the winged altar can display different scenes on weekdays, Sundays or holidays, based on the motifs and type of decoration (painted panels or reliefs), it is also called a liturgical altar.
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