Originally erected in the late 6th century as the Diocese of Cambrai, when the episcopal see after the death of the Frankish bishop Saint Vedast (Vaast) was relocated here from Arras.

After the revolt by Duke Gilbert of Lorraine collapsed at the Battle of Andernach of 939, Louis IV of France renounced the Lotharingian lands, and in 941 Henry's son and successor King Otto I of Germany ratified all the privileges that had been accorded to the Bishops of Cambrai by the Frankish rulers.

[1] In the 14th and 15th centuries, the bishopric was temporarily a protectorate of the Burgundian dukes, which in 1482, as part of the inheritance of Mary the Rich, passed to her husband Maximilian I of Habsburg.

Nevertheless, the creation in 1559 of the new metropolitan See of Mechelen and of eleven other dioceses in the Southern Netherlands was at the request of King Philip II of Spain, in order to facilitate the struggle against the Reformation.

By the Napoleonic Concordat of 1801, Cambrai was again reduced to a simple bishopric, suffragan to Paris, and included remnants of the former dioceses of Tournai, Ypres, and Saint Omer.

The English college of Douai, founded by William Allen in 1568, gave in subsequent centuries a certain number of apostles and martyrs to Catholic England.