The prince and prrincess of Wales are not actually expected to make their wedding trip to Chillicothe, Ohio, the home of one of Diane Spencer's forbears, but (for the record) they certainly have been invited to do so.

The princess (as she will be after her marriage at St. Paul's Cathedral in London on July 29) has a slight American connection some generations back. Needless to say her American great-great grandparents have other descendants besides Lady Diana; indeed, it is probable they did not have the throne of England in mind at the time they started having babies, and would be somewhat surprised that a king of England in say, the year 2020 would be their descendant.

Now many Americans find in their own families a great-aunt or a grand-mother or a great-uncle Will or some such person who is the family authority on gloire, and who can introduce into general conversation (at the proper time to startle people) the little tidbit that Charlemagne was a cousin on our mother's side and Caligula, oddly enough, on our father's.

"Oh," is the usual response to this information. At which point family archivist generally takes over the conversation and things go down hill from there.

But I certainly expect that once the princess of Wales' American connection becomes generally known we shall see half of this continent boarding Concordes and steamers and open rafts to sail to London -- to sail to the palace -- to have tea with the family.

Instantly the question arises -- for one would not wish to barge in on the royal couple unless one were truly of the family -- whether one is a cousin or not.

If you are indeed a cousin, I reckon the Windsors are like everybody else and are resigned to receiving you when you drop in. Otherwise they might say please go get lost when you ring the bell.

To get to the bottom of this, so that Americans can arm themselves with the right credentials, I have consulted with two genealogists who know whereof they speak. They are Gary Boyd Roberts of Boston, a man so far gone in his specialty that he does nothing else and who tells me he makes a financially poor but otherwise rewarding living from ancestral research; and William Addams Reitwiesner, who has been with the Library of Congress' Congressional Research Service for nine years and who states he is absolute dust beneath the chariot wheels there, but who loves the place which is so rich in material for genealogical research.

These men both know precisely, not vaguely, who is and who is not related, and this may be the place to say that while great-great-great-great-great-grandfathers have cast a wide net indeed, still the catch has not been universal. There are yet a few fish not in it.

To be quite sure that one is related to persons of consequence it may in some cases be necessary to go back to Adam. In most families, however, one need not go back so far to turn up persons of immense eminence (at least as far as Aunt Maude is concerned). Also let me say that "cousin" is one of the most valuable words in the language since it covers relationships that may be extremely close genetically and also covers relationships so remote as to be astronomical. This is well understood in Virginia, Tennessee, Carolina and elsewhere.

Now the princess' essential American connection is her great-great-grandfather, Frank Work, of Chillicothe, Ohio and later of New York; and his wife, Ellen Wood Work. Now this Mrs. Work was a daughter of John Wood of Shepardstown, W. Va., and Ellen Strong of Philadelphia. o

Ellen Strong -- we are about to hit pay dirt here -- was the daughter of Joseph Strong of Coventry, Conn., and Rebecca Young of Philadelphia. This Mr. Strong, who was a graduate of Yale in 1788, himself had 25 percent well-documented forbears who lived in New England in the period between 1623 and 1650.

To remind you how this works, a cousin of our Joseph Strong had 28,000 descendants by 1870, Roberts assured me, and if you contemplate how many descendants those 28,000 persons have had within another century, you will see that we are indeed of the family of man. One of my own great-grandmothers was May Roberts, a well-known intellectual (according to my late grandmother) of the day who went to college which only strange intellectual women did then. I have some candlesticks of hers. Who can doubt I am closely related to Mr. Roberts the genealogist and who can doubt he will have me inside Buckingham Palace within the year? But back to our parsnips:

"This has caused some excitement in Chillicothe, as you can imagine," said Roberts, "and they have invited the royal couple to honeymoon there." He burst into laughter.

"What are you laughing about?" he was demanded. "You can do worse than spend your honeymoon in the gentle green landscape of Ohio. Probably the elevators work out there and you can probably get cream that actually whips and there is much to be said for it."

Roberts was still in a fall-off-the-chair mode but collected himself to shuffle through copious notes he had brought with him:

"Let's see. Frank Work, to get back to him, was a druggist's clerk in Chillicothe [other documentation shows he was a dry-goods clerk -- Ed.] as a young man, but he went to New York to seek his fortune. There he met Commodore Cornelius Vanderbilt -- both men were greatly interested in horses, it was a bond between them. At one point Frank Work was in trouble and asked the commodore for financial advice, which he took and which was excellent. It was the base of Work's own fortune of $15 million," Roberts recounted.

"The princess is a distant cousin of the Marquis de Sade," said Reitwiesner, who feared perhaps the conversation was getting a bit technical or dry.

He thought a newspaper hack would rise to that bait.

But we have standards, you know, and if we say the princess has American cousins, then by the grace of God we propose to document the assertion, and the Marquis de Sade can wait for another night.

"She is also distantly related to Hermann Goering," said Reitwiesner, who was beginning to show signs of being a royal troublemaker, one of those annoying people who believe in the whole truth though the heavens fall.

"Perhaps we can postpone Jesse James," I ventured (for one of Reitwiesner's research papers is called "The Relationship of Lady Diana Spencer to Various Persons," and he underatandably kept tossing out names he thought would prove of interest. And so they are, but the task here is to pin down the essential blood relationship by which Americans may be guided in their future dealings with the Windsors).

Back to Work, I always say, and certainly said many times with these two genealogists.

"When Work was 80," said Roberts, "he had a sick horse and spent all night in the stall with him."

Ah, Birth and breeding tell. You show me a man whose values are rightly sorted out and I'll show you the progenitor of kings. The American and Anglican honor is essentially identical. We may have faults -- certainly the English do -- but when the chips are down we may be described in a nutshell as men who slumber not when Crock of Gold is off his feed or breaks a leg or has to be put down. For that matter we do not abandon Old Pearl long after she no longer pulls the plough. Are we not rightly known among all other nations as the ones who forgive almost anything except beastliness towards old animals (excluding people, of course, who are supposed to take care of themselves).

Say "green pasture" or "field at sunset" or "stabled warm" in any company that speaks our most blessed language and you will see every eye fill up.

So this Frank Work was a good man.

His daughter, Frances Ellen Strong, who was the princess, great-grandmother, married James Boothby Burke Roche, the third Baron Fermoy. There is a beautiful daffodil named 'Fermoy,' by the way, and by the way the Burke Roches do not use a hypen in their double name.

There son, Edmund Maurice Burke Roche, the fourth baron, married Ruth Sylvia Gill.

And their daughter, Frances Ruth Burke Roche, married Edward John Spencer, the eighth Earl Spencer. And their daughter is Lady Diana Spencer, so there you have it, from Chillicothe on.

Now then. There is not all that much Americans can do with Frank Work, fine man though he was, but once you start exploring his and his wife's relatives and going back a bit, you wind up with all those 17th century worthies.

All you have to do is go back yourself until you hit one of them and you have it made.

"Tell me," I said, "how you answer the reproaches you say you keep getting, that you are spending your life on trivia matters of genealogy. You clearly think it important. In a sense you might say all scholarship is important, but how did you choose genealogy?"

"I am interested in the social evolution of the western world," said Roberts, "and you can tell a great deal from studying pedigrees -- how classes emerge and rise and fall."

"But," I argued, "isn't it true that all people whose families have lived in the same geographical place a few generations are inevitably related, at least as closely as second cousin, to all others? And if so, what is the point of knowing the precise relationship?"

"Well," said Roberts, "you are only partly right. There are people who move in, who have not always lived there, and they are not related. In Virginia it is true that old families are all related. In fact I have a theory that when the old Eastern families kept marrying one another it made people rather short, and when they moved out in the 19th century they got new blood and started getting taller.

"I know people think genealogists are offbeat. I myself am resigned to never making more than $7,000 a year. And Bill here is content with a (low status) job at the Library of Congress, just so he can be near the things he needs for his research. At least we are absorbed in our work, we are dedicated. Have you seen my work in 'Burke's Presidential Families' in which we trace the pedigrees of all American presidents through Reagan?

"I said something about inbreeding making people short. Let me say that Bill here, though he is short, is not all that inbred," Roberts said, hoping he had not hurt Reitwiesnerhs feelings. "Actually, he is a great authority on continental European genealogy. He is a preeminent authority on the influence of Syrian and Armenian families in the German noble houses. oThe Crusades, you know."

One was tempted, of course, to reflect on Prussian rug salesmen, but back to Work:

"How closely related are the several thousand American relatives of the princess?" I persisted.

"She has a second cousin living on Oliver Street here in Washington. She has a tenth cousin working here at The Washington Post. Most of them are seventh to tenth cousins.

"No," he went on after I had mentioned a friend of mine who is an American cousin of the princess, "it is virtually impossible that the first child of the royal union will be named Ben. Ben is not a royal name."

"I have always regarded Ben as a royal name," I interposed. "All American do."

"Well, don't count on it. The thing is that if her son becomes king of England he will be one-sixteenth American, the first time this has ever occurred. That king would be eligible for various American hereditary societies. Diana Spencer herself is eligible through three different ancestors for the Daughters of the American Revolution. She is a first cousin six times removed of Nathan Hale. Lady Diana is one-fourth Scots, one-sixteenth Irish and Anglo-Irish, and one-eighth American. The rest is English, except for bits and pieces of other things," Roberts concluded.

Bits and pieces? But Reitwiesner was off on another tangent:

"Presidents Carter and Nixon are sixth cousins. They are both ninth cousins of President Harding."

Roberts said the new princess of Wales has few southern connections in America, almost all Yankees. We spoke briefly on the crosses one must bear -- one is hardly responsible for one'e forbears -- and Roberts mentioned that other American (Wallis Warfield of Maryland) associated with the British royal house. He did not regard her family as especially notable.

"What a thing to say," I cried. "The duchess of Windsor was very well connected indeed with big Maryland families, we have always thought."

"Well, no doubt," said Roberts, "but all you really get from Maryland is fine old families marrying fine old Maryland families."

"Is that worse," I inquired, "than peddlers and moneygrubbers marrying peddlers and moneygrubbers as in New England?"

"But New England," Roberets started. . .

"New England is where they have Yale," he was reminded, "and where they exalt anybody that ever built a shed."

"How did you know I went to Yale?" Roberts asked.

"And the duPonts," I reminded him, ignoring the Yale question for I do not disclose some of my sources, "are simply unarguably an important American family no matter what you think.".

Reitwiesner, the one that likes to make trouble, appeared to be enjoying himself, but provided, after all, some quite respectable American connections for the princess:

She is a second cousin 12 times removed of Lewis Burwell of Virginia, his researches have disclosed. She is a second cousin nine times removed of John Coke; a first cousin 13 times removed of George Evelyn (these are all Virginians, of course); a third cousin eight times removed of William Fairfax; a first cousin 11 times removed of William Berkeley; a sixth cousin 10 times removed of Peter Montague; a fifth cousin nine times removed of Daniel Parke Custis.

Both Roberts and Reitwiesner, I am happy to say, are in the family. Through five different lines Reitwiesner is her cousin, a twelfth cousin once removed, and Roberts is a quadruple twelfth cousin once removed and a double twelfth cousin twice removed of Lady Diana.

"Now about the invitations," I reminded him, "to the next big family gathering. You are, ah. . . ."

"Of course. I am doing what I can." [He did not actually say this. But I was sure it was what he meant.]