 On 14 September 1823, the territory of the diocese was extended to include Luxembourg, which had previously been part of the Diocese of Metz.After the Belgian Revolution of 1830, a vicar apostolic was appointed for those parts of Luxembourg under Dutch control.As a result of the Treaty of London (1839) formalising the partition of Luxembourg between the Grand Duchy of Luxembourg and the Belgian Province of Luxembourg, in 1840 ecclesiastical jurisdiction over the whole territory of the grand duchy was given to the vicar apostolic of Luxembourg, its loss to the Diocese of Namur being formalised on 7 October 1842.