Why is Lady Helen Taylor now referred to as The Lady Helen Taylor? I read it was because her brothers are not in the line of succession, since her elder brother married a Catholic and her younger became a Catholic. What then does "The" signify in her case?
Lady Helen Taylor was always styled as The Lady - first as
The Lady Helen Windsor, and now as
The Lady Helen Taylor. It has nothing to do with her inclusion in the Line of Succession and just
signifies she is a daughter of a Duke.
The daughters of of Dukes, Marquess and Earls are accorded the definite article to signify their position; the style is prefixed to the given and family name of the woman (The Lady Helen Windsor).
If the lady marries a commoner, she retains that styling (The Lady Helen Taylor). Thus, Diana was The Lady Diana Spencer before her marriage, the daughter of Prince and Princess Michael of Kent is The Lady Gabriella Windsor, the daughters of the Duke and Duchess of Gloucester are The Lady Rose Gilman and The Lady Davina Lewis, and so on.
The definite article is also used
for wives of Peers, although in a slightly different way: it is added to the husband's title (The Lady Smith).
A widowed peeress retains the definite article with the addition of Dowager (The Dowager Lady Smith). In case of
wives of the younger sons of Dukes and Marquesses (who are by courtesy known as Lords), they are known by their husband's given and family name with The Lady prefixed to it (The Lady John Smith). Those who are entitled to the styling as The Lady include
female recipients of the Order of the Garter and Order of the Thistle; in their case, the title is prefixed to their given and family name (The Lady Marion Fraser).
The definite article "The" is to be used in all cases except after a divorce when the woman doesn't hold the courtesy style in her own right. For instance, The Lady John Smith would be known as Anne, Lady Smith after the divorce).
During the Middle Ages, Princesses were rarely actually called Princesses but rather were referred to as The Ladies too; for instance, the daughters of Henry VIII were known as The Lady Mary (future Mary I of England) and The Lady Elizabeth (future Elizabeth I).
