The diocese was constituted as a suffragan see of the new metropolitan see of Cambrai by the papal bull of 12 May 1559 establishing the new bishoprics in the Low Countries.

After suppression in the French period the diocese was re-established by the Concordat of 1801, its extent matching that of the Department of Sambre-et-Meuse, and as suffragan of the Archdiocese of Mechelen.

After the Belgian Revolution of 1830, a vicar apostolic was appointed for those parts of Luxembourg under Dutch control.

[3] In 1907, the Diocese of Namur numbered 583,722 inhabitants, 36 deaneries, 37 parishes, 677 succursals, 96 auxiliary chapels, 111 curacies paid by the State.

The first dean, Frederick of Lorraine, brother-in-law of Albert II, about 1050 secured from Mainz Cathedral a portion of the head of Saint Albinus, to whose patronage the collegiate church was dedicated.