Count, theoretically the ruler of a county; known as an Earl in modern Britain (The Rt Hon) The Earl of London My Lord or Dear Lord London My Lord or
Your Lordship or Lord London An earl has the title Earl of [X] when the title originates from a placename, or Earl [X] when the title comes from a surname. In either case, he is referred to as Lord [X], and his wife as Lady [X]. A countess who holds an earldom in her own right also uses Lady [X], but her husband does not have a title (unless he has one in his own right).
The eldest son of an earl, though not himself a peer, is entitled to use a courtesy title, usually the highest of his father's lesser titles (if any); younger sons are styled The Honourable [Forename] [Surname], and daughters The Lady [Forename] [Surname] (Lady Diana Spencer being a well-known example).
Your Lordship or Lord London An earl has the title Earl of [X] when the title originates from a placename, or Earl [X] when the title comes from a surname. In either case, he is referred to as Lord [X], and his wife as Lady [X]. A countess who holds an earldom in her own right also uses Lady [X], but her husband does not have a title (unless he has one in his own right).
The eldest son of an earl, though not himself a peer, is entitled to use a courtesy title, usually the highest of his father's lesser titles (if any); younger sons are styled The Honourable [Forename] [Surname], and daughters The Lady [Forename] [Surname] (Lady Diana Spencer being a well-known example).