Looking up in amazement as Christ ascends into heaven are the twelve apostles. Kneeling with them is the Virgin, the only one to have a halo. Although few of the men can be identified, John the Evangelist is recognizable. He is the blond, beardless youth dressed in green who solicitously puts his arm around Mary. Surrounding the risen Christ are a group of Old Testament personages who either predicted or foreshadowed events of his life on earth.
The gold background, bright colors, and compact space reveal the lingering influence of the International Gothic. However, a new spirit of visual observation also can be detected. The sharp, angular folds of the drapery evoke the perception of real human forms beneath the material. Further, the faces of the apostles reveal a broad variety of human emotions.
This panel was once part of the high altar in the Cistercian abbey church of Marienfeld at Münster. At its center was a richly gilded sculpture of the Virgin and Child. Folding wings extended from this core with pictures on the fronts and backs. When the shutters were open, eight scenes -- including the National Gallery's painting -- revealed the story of Mary's life. In the closed positions, eight other subjects recounted Christ's Passion.
More information on this painting can be found in the Gallery publication German Paintings of the Fifteenth through Seventeenth Centuries, which is available as a free PDF https://www.nga.gov/content/dam/ngaweb/research/publications/pdfs/german-painting-fifteenth-through-seventeenth-centuries.pdf