Baptismal font
During the period typology became the dominant approach in theological literature and art to interpreting the bible, with Old Testament incidents seen as pre-figurations of aspects of the life of Christ, and shown paired with their corresponding New Testament episode. Often the iconography of the New Testament scene was based on traditions and models originating in Late Antiquity, but the iconography of the Old Testament episode had to be invented in this period, for lack of precedents. New themes such as the Tree of Jesse were devised, and representations of God the Father became more acceptable. The vast majority of surviving art is religious. Mosan art was an especially refined regional style, with much superb metalwork surviving, often combined with enamel, and elements of classicism rare in Romanesque art, as in the Baptismal font at St Bartholomew's Church, Liège, or the Shrine of the Three Kings at Cologne, one of a number of surviving works by Nicholas of Verdun, whose services were sought across north-western Europe.