The treaty of Meaux-Paris, signed in 1229 at the end of the Albigensian Crusade, handed the French crown land to the west of the Rhone from Pont-Saint-Esprit to the Mediterranean and a joint interest in the city of Avignon. In 1290 the French king, Philip IV, ceded his claim to Avignon to his father's cousin, Charles II of Naples who was the Count of Provence through his marriage to Beatrice of Provence.
The Benedictine Abbey of Saint-André occupied a strategic position on Mount Andaon within sight of the town of Avignon which lay on the other side of the Rhone. Mount Andaon is a rocky outcrop with steep sides to the north and the east that rises 50 m above the floodplain of the Rhone.
The abbey had been founded at the end of the 10th century and possessed extensive property with over 200 churches spread over a wide area of southern France. In 1290 Philip IV instructed Adam de Montcéliard, the sénéchal of Beaucaire, to negotiate an agreement with the abbey to cooperate in the defense of the right bank of the Rhone. The paréage treaty signed in 1292 specified that Philippe le Bel could build a fortress with a permanent garrison next to the abbey and a castle by the river. The abbey surrendered temporal power but obtained protection from the unwanted pressure from the city of Avignon which wished to control both banks of the Rhone. By 1302 fortifications, including an initial Tour Philippe-le-Bel, had been built at the western end of the Pont Saint-Bénézet which lay less than kilometer from the abbey. In 1309, Pope Clement V moved the papacy from Rome to Avignon.
The fortress of Saint-André, with the curtain wall that surrounded the abbey, was built in several stages during the first half of the 14th century. The surviving manuscripts do not allow the construction to be precisely dated. A châtelain is mentioned in documents dating from 1314 and 1344, a guard is mentioned in 1318. The carved crest placed by the abbey above the entrance is dated 20 July 1367. This was probably when modifications were made to the entrance arch. The fortress was continually occupied by officers of the crown up to the time of French revolution.
The fortress was clearly visible from Papal State across the Rhone in the town of Avignon and was intended to demonstrate the power of the Kingdom of France.References:
The Externsteine (Extern stones) is a distinctive sandstone rock formation located in the Teutoburg Forest, near the town of Horn-Bad Meinberg. The formation is a tor consisting of several tall, narrow columns of rock which rise abruptly from the surrounding wooded hills. Archaeological excavations have yielded some Upper Paleolithic stone tools dating to about 10,700 BC from 9,600 BC.
In a popular tradition going back to an idea proposed to Hermann Hamelmann in 1564, the Externsteine are identified as a sacred site of the pagan Saxons, and the location of the Irminsul (sacral pillar-like object in German paganism) idol reportedly destroyed by Charlemagne; there is however no archaeological evidence that would confirm the site's use during the relevant period.
The stones were used as the site of a hermitage in the Middle Ages, and by at least the high medieval period were the site of a Christian chapel. The Externsteine relief is a medieval depiction of the Descent from the Cross. It remains controversial whether the site was already used for Christian worship in the 8th to early 10th centuries.
The Externsteine gained prominence when Völkisch and nationalistic scholars took an interest in the late 19th and early 20th centuries. This interest peaked under the Nazi regime, when the Externsteine became a focus of nazi propaganda. Today, they remain a popular tourist destination and also continue to attract Neo-Pagans and Neo-Nazis.