A royal descent is a person descended from a past or present monarch.
Both geneticists and genealogists have attempted to estimate the percentage of living people with royal descent. From a genetical perspective, the number of unprovable descendants must be virtually unlimited if going back enough generations, according to coalescent theory, as the possiblity increases exponentially following every century back in time. In other words, the number of descendants from a monarch increases as a function of the length of time between the monarch's death and the birth of the particular descendant.
As for descendants of genealogical documented lineages, various estimated figues have been proposed. For instance, Mark Humphrys, a professor of computer science at Dublin City University in Ireland, and genealogy enthusiast, estimate the people of provable genealogical ancestry from medieval monarchs to millions. In any case, the percentage of genealogical descendants are bound to increase with time; not only with every new generation but also due to more extensive combination of individual efforts in genealogy software, including international services available online.
In genealogy, royal descent is sometimes claimed as a mark of distinction and is seen as a desirable goal. However, due to the incompleteness and varying uncertainty of existing records, the number of people who do claim royal descent tend to be higher than the number who can actually prove it. Historically, pretenders, impostors and those hoping to improve their social status have often claimed royal descent, some with fabricated lineages. The importance of royal descent to some genealogists has been criticized.