Royal intermarriage

Royal intermarriage is the practice of members of royal families marrying into other royal families. It was more commonly done in the past for reasons of state and in order to maintain the purity of bloodlines. Historically, royal marriages often sealed alliances or pacts, and were instrumental in many countries' diplomatic relations. Over many generations, intermarriage between royals came to a point where most royals became related to all other royals.

Marriage for purity

Royal intermarriage became practiced widely as a way of ensuring all members of a royal family were descended from royalty as opposed to commoners. This class distinction gave rise to many house laws stipulating who a dynast could marry to have an "equal marriage"; marriages outside this were considered morganatic. This often occurred in monarchies with such small courts that it became a means of maintaining relations, such as Europe and princely India under the British Raj.

Morganatic marriage

If a member of royal family married someone not of appropriate status, they sometimes lost succession rights, titles, or other varied royal privileges. A frequent occurrence was for their children and spouse to receive a lesser title, although these cadet branches sometimes were deemed suitable for marriage into other families. This occurredwhen Prince Alexander of Hesse and by Rhine married the lesser Countess Julia von Hauke. Julia and the morganatic children of this union were given the style of Serene Highness and title of Prince(ss) of Battenberg. The Battenberg family later married into the royal families of Sweden and Spain, and descendants into the royal families of Britain, Greece, Denmark, and other countries. Similarly, the Teck family, from which Queen Mary of the United Kingdom came, was a morganatic branch of the royal House of Württemberg.

Interbreeding

Over time, due to the relatively small pool of potential consorts, the gene pool of many regional royal families grew progressively smaller, until all European royalty were related, often to their consorts as well. This also resulted in many being descended from a certain person through many lines of descent, such as the numerous European royals and nobles descended from the British Queen Victoria or King Christian IX of Denmark. The House of Habsburg was infamous for its inbreeding, with the Habsburg lip cited as an ill-effect. The Habsburgs frequently married within the family and the closely related houses of Bourbon and Wittelsbach, uncle-niece and double-cousin and first-cousin unions occurring frequently.

Modern examples

British and Spanish royal families

A well-known example of royal intermarriage and interrelation today is that of Elizabeth II of the United Kingdom and Prince Philip, Duke of Edinburgh (born a Prince of Greece and Denmark). Prince Philip is the son of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg, whose mother Princess Victoria of Hesse and by Rhine and paternal grandfather, Prince Alexander of Hesse and by Rhine, were both members of the same paternal family. Princess Alice's father's brother, Prince Henry of Battenberg, meanwhile, married Princess Beatrice (a daughter of Elizabeth II's great-great-grandmother, Queen Victoria). Their daughter, Victoria Eugenie of Battenberg married King Alfonso XIII of Spain, and her grandson, the present king, Juan Carlos, married Princess Sophia of Greece & Denmark, whose father was a cousin of Prince Philip, Duke of Edinburgh. Alternatively, Queen Elizabeth's great-great-grandfather, King Christian IX of Denmark, was also Prince Philip's great-grandfather. They are also related several times through Princess Sophia, Electress of Hanover.

Family tree

Grandchildren of Queen Victoria and King Christian IX

In early twentieth century Europe, the grandchildren of Queen Victoria and King Christian IX were prevalent throughout most of Europe's royal courts. The British throne was occupied by King Edward VII, who was married to Princess Alexandra, the daughter of King Christian IX of Denmark. German Emperor William was the son of German Emperor Frederick III and Victoria, Princess Royal, the eldest daughter of Queen Victoria. Another of Victoria's daughters, Princess Alice, married Grand Duke Louis IV of Hesse and by Rhine, whose daughter Princess Alix became Empress of Russia as the consort of Tsar Nicholas II. Nicholas himself was the son of Tsar Alexander III and Princess Marie Sophie Frederikke Dagmar, another daughter of King Christian IX of Denmark.