We had to proceed, from 944, to the elevation of the relics of Saint Barnard which were placed in a silver shrine to the left of the main altar dedicated to the holy apostles.
On the occasion of this election, Guillaume de Clérieu, Léger's father, gave up his rights to the town of Romans in favor of his son.
The archbishop and abbot Léger (1025-1070) built a bridge over the Isère, now called "Pont Vieux", allowing the development of the city.
In 1049, he authorized the chapter to build a cloister against the southern flank of the abbey and houses to the west of the church for the staff not living together in the enclosure.
The church was damaged during the wars of religion, in 1562 (ransacking by the Baron des Adrets) and in 1567 by the bands of Cardé and Geyssans who completed the ruin by bringing down the vaults and steeples.
If the monks estimate the cost of the damage to the Saint-Barnard church alone at 200,000 pounds, the prices and the remains of the Gothic paintings show that the vaults of the transept resisted.
Work was carried out gradually from the choir to the nave and was completed in 1720 with the elegant gallery which waited until 1843 for the installation of the organs.
Church listed in 1840 by Mérimée; he could not prevent the municipal officials from having the cloister destroyed to build the Quai de l'Isère.