A work in compartments, levels and multiple or single panels, the Altar-piece is, together with the fresco, the most prevalent type of painting in Italy between the 12th and the late 15th century. Its name, of Spanish origin, signifies “the back of the table”. Most often in poplar wood, the retable was always placed on the altar, where the priest conducted mass, at the most sacred place in the church. A composition of several fixed or mobile panels is called a polyptch. A diptych is composed of two panels and a triptych of three; a pala of one. The predalla designates the lower part of the altar-piece and is most frequently independent of the retable itself and composed of several juxtaposed panels. Many altar-pieces were taken apart and scattered and their elements were often framed or transformed into trestles for easel painting.
