 The diocese comprises all of the department of Allier in the region of Auvergne.The diocese was created in 1788, but the new bishop, Étienne-Jean-Baptiste-Louis des Gallois de la Tour, although appointed by King Louis XVI on 29 May 1789, had not been approved (preconized) by Pope Pius VI before the outbreak of the French Revolution in July 1789.Under the Civil Constitution of the Clergy (12 July 1790) there was erected a diocese of Allier, with a Constitutional Bishop resident at Moulins.