The central element of Christian liturgy, the altarpiece, placed above the alter, is a traditional work of art - a panel placed above and behind the altar, generally in a rectangular form, and made of the most varied materials and techniques, such as sculpture in stone, marble, alabaster, wood, ivory, metalwork, painting on stone, or wood etc. In its collections, the Musee du Louvre holds some remarkable examples of early altarpieces, which are complemented in the forthcoming exhibition by works from other museums and churches. They are mainly French altarpieces (retables), a reflection of the importance of France, and especially of Paris and Saint-Denis, in the genesis of these works of art. Although central to Christian liturgical decoration, altarpieces did not emerge until the 12th century. This book, and the accompanying exhibition recalls the origins of the genre and follows its evolution up to the early 15th century, when altarpieces assumed their more familiar forms.