 Many of the magnificent stained glass windows of France, including the famous windows of Chartres, date from the 13th century.Far fewer large windows remain intact from the 12th century.One such is the Crucifixion of Poitiers, a remarkable composition that rises through three stages, the lowest with a quatrefoil depicting the Martyrdom of St Peter, the largest central stage dominated by the crucifixion and the upper stage showing the Ascension of Christ in a mandorla.