Did you know that 2 Avignon popes came from the abbey? Yes, the Italian Corrado del Suburra (Anastase IV) in 1153 and the English Nicolas Breakspeare (Adrian IV) in 1154! This one was the only English pope in all History...
The tradition says that at the end of the 1st century, first bishop of Avignon, saint Ruf, founded a small chapel and a convent outside the city walls, near the river Durance. Ruf? He was Simon's son, the one who helped Jesus to carry his cross.
Disciple of saint Paul, he came in Provence to evangelize Avignon: he was its first bishop, circa 70. The little church was mentioned since the beginning of the 10 century as belonging to bishop of Avignon.
Then, 4 canons arrived from Avignon cathedral, Notre-Dame-des-Doms: Pontius, Arnaud, Odilon and Durand. Our 4 fellows decided to move in the first monastery, raised by Ruf: in 1039, they founded Saint-Ruf order. So they launched the building site.
They raised religious buildings and the church, little by little extended though centuries. Aah... but out abbey was plundered by Raymond VI’s troops during the Cathars’ crusades in the 12th century, so our monks had to run away on an island near Valence...
When they came back, whoa! They only found ruins. So they decided to rebuild the monastery and to fortify it: crenelates and machicolations mixed with the soft and nice religious architecture... But the church was abandoned: in the middle of the 18th century, Saint-Ruf’s abbot simply razed it! He only left the bell-tower, that we still can see.