Royal descent

A royal descent is a (often through female or illegitimate lines) from one or more s or s.  Royal descent is sometimes claimed as a mark of distinction. However, the number who can prove such a descent is much smaller than the number who actually have it.

European royal descent
It is a long tradition that royalty marry only those of their own class. Because of this, "the ruling houses of Europe have always been closely related to one another", and the descent from one monarch will be found in many other families - all present European monarchs, and a great many pretenders, are descendants of, for example.

The practice of restrictive marriages has been noted as having increased over the years: "the passage of time strengthened the conviction that royalty only allied with royalty, and from the sixteenth century onwards marriages between crown and commoner became rarer and rarer." This is one reason why descent from more recent monarchs is rarer amongst commoners than from monarchs further back.

Several descendants of European royal families who live ordinary lives today are descendants from the children of royalty. Since illegitimate children could not marry into other royal families (because their status made them unacceptable to most monarchs), these children had to marry or  families from their own country.

Another reason for the greater number of descendants from chronologically distant monarchs is that likelihood of descent from a monarch increases in direct proportion to the length of time between the monarch's death and the birth of the particular descendant. Thus, "statistically, most of the inhabitants of Western Europe are probably descended from William the Conqueror; they are equally likely to be descended from the man who groomed his charger."

American royal descent
Royal descents can also be found for many Americans who are descended from 17th-century who had royal ancestry. There were several hundred colonists who have traceable royal ancestry; The Royal Descents of 600 Immigrants by is the definitive resource, and The Royal Ancestry Bible by Michael Call gives descents for 300 colonists who have at least 20,000 American descendants. The state in which the greatest number of these immigrants settled was Virginia.

The early colonists were typically younger children of English noble or middle class families who came to America looking for land because, given their status, they could not inherit. Many of these immigrants were of high standing where they settled and some could often claim descent from royalty, in particular that of 's royal houses, through a or.

Since these families emigrating to the New World had no one else of their rank to marry, many of them intermarried with one another through several generations. Over the two hundred years or more since the colonial land grants, several families had interwinded their branches to the point that almost everyone was somehow related to everyone else. One writer observed, "like a tangle of fish hooks".

More than half (26 out of 41) of the have had a traceable royal descent or a wife with traceable royal descent.

Proving royal descent
Royal descent is easier to prove than descent from less notable ancestors, because genealogies and public records are typically fuller, better known and well preserved in the case of royal descent than in the case of descent from common people. It is only since the that family history has been an interest pursued by people outside the. Hence, the continuous lines of descent from royal ancestors are much better researched and established than those from other ancestors. Until the record system in the, and  in the , family records are fuller for landowners than for ordinary people.

Between 1903 and 1911, the Marquis de Ruvigny published volumes entitled The Blood Royal of Britain which attempted to name all the then-living descendants of. He gave up the exercise after publishing the names of about 40,000 living people, but his own estimate was that the total of those of royal descent who could be proved and named if he completed his work at that time was 100,000 people. His work, however, was heavily dependent upon those whose names were readily ascertainable from works of genealogical reference, such as and.

It has been estimated that probably as many as 150 million Americans have traceable royal European descent. Which is about 60% of the population. The English geneticist Professor Stephen Jones estimates 25% of the British population being descended from the Plantagenets.

The phrase "English descent" does not, of course, mean "purely English descent". As soon as an immigrant family marries into an indigenous family, it acquires all the ancestors of its indigenous parent, and is therefore no less likely to be able to claim a royal descent than a non-immigrant family.

Lineage groups for royal descendants exist, such as the National Societies of Royal and Noble Ancestry, which is made up of the Society of Charlemagne Ancestry, Society of Magna Charta Ancestry, and Society of Royal Bastard Ancestry.