Exterior view

The Romanesque Basilica of St. Peter and St. Paul, built principally between 1088 and 1130, was the largest church in the world until the erection of St. Peter's in Rome. Cluny's basilica was in great part demolished in the early 19th century, but the ruins of the main southern transept, dominated by a great belfry tower, testify to its former glory.

Cluny III, as it was rebuilt at the end of the 11th century and early 12th century and destroyed by the French themselves in 1810, had two transepts, each with an octagonal tower over the crossing. The more important of these, the one farther west, had octagonal towers to the right and left of the crossing (one of these survives), and two eastern apses to each arm. The eastern transept had four apses too. Moreover, the chancel apse had an ambulatory with five radiating chapels. Thus it is a structure so complex as earlier centuries in the West could not have conceived.

The photo shows the surviving southern transept. The view of the church as it might appeared in the sixteenth century can be seen in the lithographs by Émile Sagot.

View the ground plan of the whole monastery site, reconstruction of its state around 1150.