Royal House

A royal house or royal dynasty consists of at least one, but usually more monarchs who are related to one another, as well as their non-reigning descendants and spouses. Monarchs of the same realm who are not related to one another are usually deemed to belong to different houses, and each house is designated by a name which distinguishes it from other houses. Strictly, a "royal house" is a dynasty whose members reign while bearing the title of king or queen, although it has become common to refer to any family which legally exercises sovereignty by hereditary right as a royal family, and its members as "royalty" or (colloquially) "royals". Historically, ruling families often consist of a senior and several junior branches, which are akin, but may have diverged in descent from a common ancestor many generations ago. The name used to refer to a royal house may or may not also be used by its members as a surname. Rather, members of dynasties are usually referred to by their titles, which may or may not also be hereditary.

Historically royal intermarriage has often brought multiple thrones to a sovereign's family. Sometimes appanages granted to cadet branches have become the nucleus of an independent monarchy—or an incentive to acquire one. Members of the same patrilineage may therefore come to rule entirely different countries and espouse national loyalties or cultural ties to nations other than the one ruled by the first monarch in the family—yet they may still acknowledge bonds based on membership in the same dynasty (e.g. Bourbon Family Compact), and may still inherit thrones or bequeath assets based upon that kinship, sometimes centuries later.

While most realms have, in the documented past, calculated membership in the royal house as descending through the male line (sometimes allowing females to inherit and sometimes not), most European monarchies have now constitutionally eliminated preference in the line of succession to the throne for males (Sweden, The Netherlands, Belgium, Denmark), and some non-European royal families have contemplated doing so (Japan, Thailand). It has long been the case that royal houses sometimes continue in the female line of descent, although that most often occurred after the dynastic male line was genealogically exhausted (e.g. Habsburg, Orange-Nassau, Romanov, Grimaldi).

Royal house names in Europe were therefore generally taken from the father; in cases where a queen regnant married a prince of another house, their children (and therefore subsequent monarchs) belonged to the house of the prince consort. Thus Queen Victoria belonged to the House of Hanover, but her male-line descendants belong to the house of her husband Albert, which is Saxe-Coburg and Gotha, a branch of the House of Wettin. The name was changed to Windsor in 1917.

Nevertheless, this rule had several exceptions in other countries: After the marriage of the then Archduchess Maria Theresa of the House of Habsburg in the 18th century to a Lorraine prince, her issue took the name Habsburg-Lorraine in order to closely associate themselves with the previous Habsburg dynasty. As mentioned, Portugal deemed the issue of Queen Maria II of Portugal and Prince Consort (later King) Ferdinand of Saxe-Coburg-Gotha to be solely members of the Braganza, and the dynasty name, as opposed to Braganza-Saxe-Coburg and Gotha.

In Russia, the death of Empress Elisabeth brought the House of Romanov to an end patrilineally. However, the Empress designated her nephew, Duke Peter-Ulrich of Holstein-Gottorp from the House of Oldenburg, as heir to the throne. After his accession, the House name of Romanov was retained, despite the fact that Peter III inherited the crown from his maternal aunt.

More recently, in the 20th century, the children of regnant females in the Netherlands and Luxembourg have retained their maternal house affiliation, and in the United Kingdom, Queen Elizabeth II's descendants by her husband, Prince Philip of Greece and Denmark, remain Windsor by letters patent, although Prince Phillip was of the House of Schleswig-Holstein-Sonderburg-Glücksburg and later surnamed "Mountbatten".

Another way in which the royal house of a given country may change is when a foreign prince is invited to fill a vacant throne or a next-of-king from a foreign house succeeds. This occurred with the death of childless Queen Anne of the House of Stuart: she was succeeded by a prince of the House of Hanover who was her nearest Protestant relative.