Why Liam is No Prince of Luxembourg

In the week since the baptism of Prince Liam, there have been several articles mentioning the young son of Prince Félix and Princess Claire as a Prince of Luxembourg. However, that is not correct. Being the child of a younger son of the Grand Duke, Liam is not a Prince of Luxembourg in accordance with the family bylaws concerning the house law published via the Arrêté grand-ducal of June 18, 2012 but instead a Prince of Nassau (as well as a Prince of Bourbon-Parma as a descendant of Prince Felix, the husband of Grand Duchess Charlotte).

Item 2 of paragraph 4b of the bylaws states that "the second and further grade male line marital descendants of the head of the house; with the exception of the offspring of the member of the house called upon to succeed to the throne according to the laws of primogeniture (item 1); and their wives by marriage according to the house rules, have the style of Royal Highness, their first name and the family name “zu Nassau” (“de Nassau”) and the title Prince or Princess of Nassau, etc. etc." The same naturally applies to Liam's sister Amalia, who is a Princess of Nassau (as well as a Prince of Bourbon-Parma).

This rule was already introduced in 1995 by way of the Arrêté grand-ducal of September 21 regulating the styles and titles of members of the Grand Ducal Family. It means that the children of Prince Guillaume, younger brother of the Grand Duke, also only carry the title of Prince/Princess of Nassau but not of Luxembourg. (As do the children of Prince Jean though they are in a bit of a special situation considering that there weren't born with the title.) Prince Robert and Princess Charlotte, children of Prince Charles and thus first cousins of the Grand Duke, are an exception to this rule as they were born before it was established. Hence, they hold the title Prince and Princess of Luxembourg, respectively, with the style Royal Highness. Prince Robert's wife and children are styled Royal Highnesses with the title Prince or Princess of Nassau.

Prince Liam is also a member of the Grand Ducal Family and Grand Ducal Line but not of the Grand Ducal House as the latter "consists of the head of state (as head of the house), the former heads of state and first grade descendants of a head of the house born within a marriage made according to the house rules."