Altarpiece: A decorated screen, panel or series of panels, fixed or movable, placed on or behind the altar. Normally it would carry paintings or reliefs. Two hinged panels comprise a diptych, three a triptych, five or more being a polyptych. A fine example of a polyptych is the 'Adoration of the Lamb' (from the Ghent Altarpiece) in the Cathedral of St Bavon, Ghent, Belgium, painted by Hubert and Jan van Eyck. At Chatsworth there is the 'Donne Triptych' by Hans Memling. The term diptych was originally applied to the Roman codex or book of two leaves or tablets fastened together.