Most families are ordinary, not special, and ethnic intermarriage, intergenerational conflict and "running away from home" are certainly as American as the rural or small-town arcadias of Norman Rockwell and Grandma Moses. Beside these perhaps bittersweet facts, however, is the grand revelation that probably sixty percent or more of the American people are descended from kings.
Such descent, shared by a majority of Americans with a sizable quantity of colonial ancestry, is usually derived through roughly 350 royally descended immigrants of the 17th and 18th centuries who have been well studied by various American scholars. In my generation these latter include David Faris (Plantagenet Ancestry of Seventeenth-Century Colonists, 2nd ed., NEHGS, 1999), myself (The Royal Descents of 500 Immigrants, GPC, 1993, 2nd ed. scheduled for 2002), Douglas Richardson, Paul C. Reed, Neil D. Thompson, Brice McAdoo Clagett, etc. A large number of these royal descents are adjusted every decade. The first edition of my work included 570 immigrants, in the expectation that 70 might be changed before the second edition. I have since added 80, deleted fifteen and changed well over 100 -- and have become something of a magnet or clearinghouse for correspondence about new discoveries in this field.
Royal descent occurs, of course, because the younger sons and daughters of kings become or marry nobles; the younger sons and daughters of nobles become or marry landed gentry; the younger sons and daughters of landed gentry become bureaucrats or professionals (clerics, university fellows, lawyers, soldiers, etc.); and the younger sons and daughters of professional elites have become the middle-class citizenry of the Anglo-American and British-derived world, in the U.S., Canada, Australia, India, South Africa, etc. And kings and royal families, of course, were derived from barbarian chieftains who led the tribes that successfully invaded, and intermarried with the patriciate of, the late Roman Empire.
Most middle-class Americans with sizable colonial ancestry and many middle-class Europeans descend from a cluster of High Medieval kings - Plantagenets from England; Capetians from France; and Hohenstaufens from Germany. Because of various intermarriages with the families of Byzantine emperors, a large number of westerners can also trace kinship to the Safavid shahs of Persia and various Mughal princes of India. Speculative descents from many ancient world cultures have been the subject of much study in the last generation and are ably summarized by Don C. Stone in Ancient and Medieval Descents Project.
In addition to the royal descents of perhaps 150 million or more Americans, probably 30 million of us (a group that may largely be subsumed in the preceding 150 million) are distantly related (8th - 12th cousins) to the late Princess of Wales and her sons, Princes William and Henry, mostly through about 20-25 New England immigrant forebears of Joseph Strong (b. Coventry, Conn. 1770). Strong is the New England-derived great-great-great-great-grandfather of the late Princess, who was 1/8th American and 1/64th New England Yankee (she was also curiously, 1/64th Armenian). The remainder of this American ancestry was mid-Atlantic, from New Jersey, Philadelphia and Maryland especially.
When this New England and mid-Atlantic ancestry of the late Princess of Wales is added to the Virginia forebears of Queen Elizabeth the Queen Mother - a subject first explored by the late Sir Anthony R. Wagner in 1939, and to which I added considerably in the Jan.-Feb. 1987 NEXUS and later Notable Kin, Volume One (1998) - the young heirs to the British throne are found to have ancestry in the three major geographic areas of colonial America (New England, the mid-Atlantic, and the South). The princes can indeed be said to occupy the genealogical center of the Anglo-American world. The Queen Mother's Virginia ancestry connects them to George Washington, Meriwether Lewis, and Robert E. Lee among other "heroes," and via Diana's New England forebears there are connections to at least two Canadian prime ministers (Sir Robert Laird Borden and Viscount Bennett). These conclusions are fully detailed and documented in American Ancestors and Cousins of The Princess of Wales (GPC, 1984), which I co-authored with William Addams Reitwiesner of the Library of Congress.
The Queen Mother and the late Princess of Wales also add to the modern British "royal stock" a large quantity of English noble ancestry ("the Whig oligarchy") and descents from various siblings or first or second cousins of 17th century immigrants to the American colonies. Prince Philip and King George VI, father of the current queen, were descended almost exclusively from the Protestant caste of European princes, centered in Germany, that seem to rule everywhere in 19th century Europe - in Scandinavian countries, Russia, the Balkans, the Netherlands, etc. The late Queen Mary, mother of George VI, was partly of noble Hungarian ancestry, however, and was descended from a sister of Vlad Dracul (the monster "Count Dracula"). Prince Philip is the great-great grandson matrilineally of Queen Victoria; the murdered czarina of Russia was his great-aunt and his mitochondrial DNA was used to disprove the identity of Anna Andersen as Grand Dutchess Anastasia. Early in life Prince Philip renounced his claims to the thrones of Greece and Denmark, Greece has ceased to be a monarchy and Denmark no longer follows the Salic Law of male-only succession. If these circumstances were different, William and Harry might be princes of three European kingdoms. Gerald Paget's The Lineage and Ancestry of H.R.H. Prince Charles, Prince of Wales, vol. 2 (1977) outlines the prince's ancestry for 18 generations; I published some additions to this massive work in the first two volumes of The Genealogist.
There is indeed then much to say about the spread of royal descents, kinships among European, royal-, noble-, and gentry-derived current populations, the composition of the ten remaining sovereign royal houses of Europe, and the genealogical centrality of these royal houses to their nations and to the descendants of colonists sent to the New World, Asia and Africa in the last several centuries. There is also much to say about our ancient ancestry and links to Egypt, Greece, Macedonia, Rome, etc. Readers of this quick survey are encouraged to peruse the books already mentioned and enjoy the magnificent feast of thousand-year pedigrees. Such lineages take us far beyond the confines of childhood, neighbors, community, class, nation and individual achievement and connect us with much of the splendor and some of the triumphs and catastrophes of Western history overall.