Maude succeeded his father in the viscountcy in 1856 but as this was an Irish peerage it did not entitle him to an automatic seat in the House of Lords.

In the latter year, he was created Earl de Montalt, of Dundrum in the County of Tipperary, in the Peerage of the United Kingdom.

Lord de Montalt married Clementina, eldest daughter of Admiral Charles Elphinstone Fleeming, in 1845, and had ten children, of whom eight survived infancy.

One of their sons, the Honourable Cornwallis Maude, a captain in the Grenadier Guards, was killed in action at the Battle of Majuba Hill in 1881.

Of their daughters, probably the best known is Kathleen, who was divorced for adultery by her first husband, Gerald Brooke, in 1886, a case which aroused enormous media interest.