There was likely a cloister on this site dating back to the construction of the Basse-Œuvre in the late 10th century. However, it has completely disappeared. The oldest remaining part, the Saint-Pierre hall, dates from the 11th century. While it may not be a part of the cloister proper, it forms the western enclosure. The oldest sections of the current cloister date from the time of the Hundred Years’ War (mid-14th to mid-15th century). The chapter house, with its Renaissance-style windows and supporting arches, is contemporary with the north transept (16th century). The brick galleries with wooden framework, in their current state, date from the late 17th century.
The Chapter House
It was built at the beginning of the 16th century, simultaneously with the north transept with which it communicates. Its elegant windows are in the Renaissance style.
It is the room where the chapter of the cathedral canons used to gather. The interior was restored in 2012.
St Pierre hall
Dating back to 1040-1050, it is the oldest building among those surrounding the cloister. This hall has housed the courthouse. Unfortunately, a fire in 1995 destroyed its timber frame.
On the street side, the facade has undergone significant alterations. Traces of the old openings can still be seen, but they are now largely buried in the ground. This indicates that the street level has been raised by nearly 2 meters since the 11th century.
The vaulted cellars
Beneath Saint-Pierre’s Hall, there is a vaulted cellar with a central aisle and lateral cells: 6 on one side of the staircase and 7 on the opposite side.
The Bishop’s Gallery
It’s a gallery that led directly from the cathedral to the episcopal palace. It spanned the street and continued on the other side with a similar structure leading to the episcopal palace, now the Departmental Museum of Oise (MUDO). The exterior of the Bishop’s Gallery dates back to the 17th century. The interior was restored in 2014.