Proper nouns with “the”

Proper nouns are the names of persons (John, Mary, Mr. Jones), of places (Africa, London, Brazil), of streets (Oxford Street, Fifth Avenue) and other items that have their own names such as days (Monday), months (April, June), languages (Arabic, French, Greek, Spanish). A proper noun begins with a capital letter.

Personal names:
A person’s own name already defines that person; we do not use the. Before a name, we can have social, professional, military and religious status words; we still do not use the:
 Mary, Peter, Susan Black, Harold Clark, Mrs. Mills, Mr. Stone, Miss Carter, Lord Devon, Professor Barnes, Nurse Kelly, Constable Parry, Captain Coles, Corporal Davis, Father Denis, Sister Angela, Brother Thomas, Bishop Lang. – but the Reverend John White for a clergyman.
We refer to a whole family in the plural with the: the Clarks, the Smiths and sometimes to a specific person who has a rather common name: There are hundreds of Reagans – the Reagan I refer to was a president.

Personal titles without a person’s name:
These usually have a prepositional phrase in item. The comes before the title even when the phrase is absent; it is always implied.