Around 1420, a rich Belgian merchant by name of Joost Vijd commisioned an altar piece displaying the Adoration of the Mystic Lamb. The order was given to Flemish master Hubert van Eyck. After his death in 1426, the painting was finished by his famous brother Jan van Eyck.
Ghent Altar Piece, officially titled Adoration of the Mystic Lamb
For a good description of the panel have a look at it's wikipedia entry or here.
The relevance of this renowned work of art to the mystery of Rennes-le-Château, was introduced by Dutch author Karl Hammer-Kaatee when he published his book Satan's Song in 2006. According to Hammer, he had merely written up the life story of a certain Tom R., a retired Dutch secret service agent who had been involved in the allied recuperation of stolen art from the nazis after World War II. Tom allegedly came to Hammer in 1990, after anonimously living in Paris for 30 years, while everybody thought he had died in a sailing accident on the Mediterrenean in 1948.
One of the pivotal topics in his book is the theft of the "Just Judges". In April 1934, two panels of the Ghent Altar Piece where stolen from St. Bavo Cathedral in Ghent where is was on display in the Chapel of Joost Vijd, its alleged commissioner. It concerned the panel of John the Baptist and the one displaying the Just Judges. The two panels had been attached to eachother back-to-back until they were separated with a saw for an exhibition in Berlin in 1894. After the diocese had received some letters demanding a ransom, the panel with St. John the Baptist was returned a month after it had been stolen. The panel of the Just Judges has been missing ever since, even though an army of professional and amateur researchers have tried to locate it. To this day, the theft of the Just Judges and the motive for it form one of the biggest art mysteries in Europe.
The story of Satan's Song, starts at the beginning of World War II. Research by Hammer and others demonstrates that even before the Belgian capitulation of 28th June 1940, a German lieutenant by name of Henry Koehn starts an investigation into the whereabouts of the Ghent Altar piece. He has been given an assignment from an unknown source very high up the nazi chain of command to investigate the whereabouts of the 'gerechten Richtern' (Just Judges). By that time, the remaining panels have been transferred to unoccupied Pau in southern France by the Belgian clergy. The Germans eventually find the Altar Piece there in August 1942, cease it and transport it to the castle of Neuschwannstein in Bavaria. In May 1945, the panels are recovered by the Americans in the salt mines of Altaussee (Austria). Three months later, the work is returned to the St. Bavo Cathedral in Ghent where it can still be seen today. The Just Judges panel has been replaced by a copy.
The genuine interest of the nazis is demonstrated by the fact that Koehn spent no less than three years trying to find the stolen panel.
the Mystic Lamb
The Adoration of the Mystic Lamb is a masterpiece in every sense of the word. The Van Eyck's were at the very forefront of painting technique. They used perspective and geometry in their paintings in a time that those techniques were in an embrionic phase and often considered secret. They also used oil in their paint, making it the first major work in oil paint, developing the technique of applying it to dizzying heights. The panels have a stunning amount of detail. One of the jewels on the panel for example. mirrors the entire chapel in which it was placed.
The official reading is that Joost Vijd commissioned the altar piece to celebrate the erection of his personal foundation. Such foundations were quite common at the time and would secure that enough masses would be said for the founder after his death. Vijd's foundation was dedicated to John the Baptist. Hammer learnt, that the foundation had only be erected in 1435, three years after the work had been completed by Jan van Eyck and 11 years after he had commissioned it.
Another anomaly is that it is almost certain that the Van Eyck brothers designed the lay-out and themes of the paintings. Vijd didn't have the background to do it. That raises a problem because in the 15th century, it was the custom that a detailed contract would be drawn up between the commisioner and the artist, certainly for bigger and expensive works. Artistic license only existed in a very limited form. In case of the Ghent Altar Piece, there was never a contract. Vijd, therefore seems to have been more the man that provided a location and who secured that this incredible piece of craftmanship would be finished by Hubert van Eyck's brother after his death, even though Jan was travelling all over Europe and possibly further in missions for his employer Philip the Good that were described in the Duke's administration as "a certain secret journey about which no explanation may be given". Hubert was buried next to the panel. It would take his brother another 7 years to complete it.
The Adoration of the Mystic Lamb is a pinnacle in 15th century art. If you pay a visit to St. Bavo's Cathedral to examine it for yourself, even today you will be amazed by it's composition and richness in colour, splendour and detail. It has amazing perspective and composition. It's not hard to imagine why Hammer-Kaatee claims that the masterpiece can't have been created for Joost Vijd and his wife alone, however rich and influential they were in Ghent at the time. No other work from anyone else at the time is so elaborate and the Vijd's weren't known for their extravaganza in other areas. The work is and was so impressive and ahead of its time that the brilliant Albrecht Dürer spent hours watching it in silence in 1521, kissing it's frame when he left the chapel. Had he recognized the geometry of it?