"THE" in noble titles

"The" is a designation only used for peers and their families. It is not used, for example, by lesser nobles of baronets, knights, or commoners (except when referring to the widow of a baronet). The wife of a baronet or knight would be Lady Burke, never The Lady Burke, while the wife of a peer would be The Lady Melgum, and a peer's daughter entitled to use a "Lady" designation would be The Lady Serena Carlow. However, when the usage is not formal, "The" may be dropped. Thus, my official title is The Duke of Warren.