Jan van Eyck was something of a diplomat as well as a painter, for when he was in the service of Philip the Good, Duke of Burgundy, he was sent on several secret missions, and in 1428 he accompanied the ambassadors of the duke to Portugal in order to paint the portrait of Isabella of Portugal, who was betrothed to the duke. There is a goodly number of works by Jan van Eyck in various galleries. The portrait of himself and wife in the National Gallery, London, is very interesting; they stand hand in hand, with a terrier dog at their feet; their dress and all the details of their surroundings are painted with great care. It is said that the Princess Mary, sister of Charles V., gave a barber who owned it a position with a handsome salary in exchange for the picture. Jan van Eyck, being twenty years younger than his brother Hubert, naturally learned all that the elder knew, and the story of his life gives him the appearance of being the more important artist, though in point of highest merit he was not the superior. Of LAMBERT VAN EYCK very little is known. It is believed that he made the copy of Hubert's great work which is in the Antwerp Museum; another work called by his name is in Louvain. MARGARETHA VAN EYCK is said to have been a skilful artist, but no one picture can be ascribed to her; she was buried beside her brother Hubert in the Cathedral of Ghent. Of course the Van Eycks had many followers. Among them were PETRUS CHRISTUS (records 1444-1471), GERARD VAN DER MEIRE (records 1447-1474), HUGO VON DER GOES (1405?-1482), and JUSTUS OF GHENT (1468-?), all of whom were good artists, but I shall pass to a more important one, ROGIER VAN DER WEYDEN (1400-1464), who was himself the head of a school of as great importance as was that of the Van Eycks. His realism was his chief characteristic, and this was so great as to make some of his works repulsive, especially his martyrdoms, in which he detailed horrors with great exactness. He also loved to paint pictures which illustrated the myths of the Middle Ages. Our illustration is from one of these works (Fig. 54). This picture is from the story that when the Roman Senate decreed divine honors to the Emperor Augustus, he consulted the Tiburtine Sibyl as to whether he ought to receive them or no. She replied to him that it was more becoming for him to go away silently, and told him that a Hebrew child should be born who should reign over the gods themselves, or that a king should come from heaven whose power should never end. Another version, which is the one this picture represents, says that the heavens opened, and a vision of the Virgin with the Saviour in her arms, standing on an altar, was shown the emperor. He worshipped it, and heard a voice saying, "Haec ara filii Dei" (This is the altar of the Son of God). Augustus reported this to the Senate, and erected an altar upon the spot in Rome where the Church of Santa Maria in Capitolio, or the "Ara Coeli," now stands.