AMBOISE, France, Sept. 27 -- The count of Paris -- otherwise known as Prince Henri Robert Ferdinand Marie Louis Philippe d'Orleans, chief pretender to the French throne -- had 2,000 of his closest friends and supporters by the Cha~teau d'Amboise today for a regal little ceremony.

Under a brilliant autumn sun beside his 15th-century cha~teau, the count marked his Capetian Dynasty's first millennium and moved to ensure its survival for a second by designating his 22-year-old grandson as his royal heir "to exercise fully the rights and duties of the Capetian House, as I did myself."

Prince Henri has turned 79, and one never knows in the royalty business.

The French have done without a king -- nicely, they will tell you -- since Louis Philippe was unceremoniously overthrown in the revolution of 1848. In fact, they seem constantly to remind one another how good it feels to be rid of royalty, shouting Vive la Republique at nearly every official ceremony.

But Prince Henri and a minuscule number of other French citizens have been brought up differently. For them, France still needs a crowned head to rise above electoral politics and play the role of arbiter and symbol of the nation. While embracing modern democracy, the royal dynasty proclaims it is ready for the call if France ever feels the need.

"I intend to pursue until my last breath the dream that today is millenary," Henri said today before turning over his powers, or pretentions, to his grandson Jean.

Jean, who has finished philosophy studies and starts law (republican) next month, responded that he is ready to take up the burden of service to France -- just in case anyone asks -- and carry on a family tradition started when Hugh Capet was crowned in 987 and founded the House of France.

"If one day circumstances lead Frenchmen to confer national responsibilities on me, it will be because I have earned their confidence by my work, my efforts and, I hope, my services rendered," he said. "The second millennium has begun in honor, peace and respect. With the help of God, long live France."

Painfully aware of history here since 1789, no one shouted "long live the king." On the other hand, no one ruined the morning's elegant tone by shouting Vive la Republique either.

As a choir of young boys sang a "Te Deum," the royal family moved among their guests to accept applause and congratulations. Symbols of royal hospitality, tables laden with food and drink, were spread about the cha~teau grounds on a bluff overlooking the Loire River.

Prince Henri also conferred on Jean the title of duke of Vendo~me, apparently hoping to make it easier to wait for the call. Dukes of Vendome have done well in the family, Henri reminded his grandson. Both Henri IV and Louis XVIII held the title before acceding to the throne.

Jean's 19-year-old brother Eudes also received a title, becoming duke of Anguouleme. Their sister, Princess Marie, got to sit on the platform of honor for the high mass and royal ceremony, but she received no title. In the Capetian line, women remain outside the path of succession, which passes from father to oldest son.

That is one part of the royal tradition that Prince Henri would rather not talk about. His eldest son, the erstwhile count of Clermont, who is Jean's father, is still around. The undeclared meaning of today's conferral thus was a generational jump in succession. This was decided because Prince Henri and his son, also named Henri, cannot get along. In fact, Henri the elder several years ago stripped Henri the younger of his title, making him a lesser noble, the count of Mortain, seated in a little Norman town known for its cable factory.

The reason for the dynastic spat, of course, is a woman. The young Henri, count of Mortain, formerly the count of Clermont, was married at the age of 24 to Marie-Theresa, princess of Wu rttemberg, a German noblewoman who took the title of duchess of Montpensier in France.

Not only did the match seem made in a genealogist's dream, but royal legend says Charles de Gaulle, then president of France, also encouraged the marriage as a symbol of Franco-German reconciliation after the three wars of 1870, 1914 and 1940.

After having two sons and a daughter with Marie-Theresa, however, the younger Henri ran off with a divorce'e, Micaela Cousino Quinones de Leon. This was bad enough, but he infuriated his father further by marrying her outside the Roman Catholic Church.

The elder Henri insisted the Capetian Dynasty existed only within the rules of the church, and that his son had therefore excluded himself from the line of succession. Seeking to underline his wishes in today's ceremony, Henri reminded the young Jean, who is still a bachelor, that hereafter he could marry only within the church and with authorization from the head of the House of France -- that is, his grandfather.

Further making the point, the duchess of Montpensier was seated on the platform of honor to the right of her sons. In real life, the two boys live with her in the tony Paris suburb of Neuilly.

But the skipped-over count of Mortain was absent. He said in a recent radio interview that his father had no right to change the line of succession, claiming that several French kings in history were known to have found time for more than one wife.

To help defend his rights, he has taken on a well-known lawyer. Tradition and history seem to be on his side. But it remains to be seen whether France's republican courts will feel qualified to decide according to ancient custom who should succeed to a throne that has not existed for 139 years.

The estranged son has not brought it up in public, but Paris gossips have been quick to point out that the aging count of Paris himself has separated from his wife. The countess went to court in February of last year to ask for a legal separation and settlement of their possessions.

Most of the family fortune has been channeled into the Conde' Foundation, which owns, among other things, the building in Chantilly where the count of Paris lives, and the Saint Louis Foundation, which owns most of the royal family's leftover property, including the Cha~teau d'Amboise.

Although other royal descendants have also claimed the French throne, the Orleans line has always considered itself the heir to Capet. The count of Paris was brought up, mostly in exile, in the belief he was rightfully king.

There is no reliable estimate of how many of the French subscribe to royalist politics, but a lot of them subscribe to royalist magazines. A welcoming-committee official at today's ceremony said the names of many invited to the event were culled from subscription lists.

In a recent book, "The Future Lasts a Long Time," Prince Henri made it clear he sees the role of monarchy as a sort of feather in the cap of democracy. Political parties should continue to play their role and a prime minister should rule with an elected parliamentary majority even with a king on the throne, he wrote.

Henri's supporters have compared their designs with the Spanish monarchy, where King Juan Carlos reigns over a country governed by elected Socialists. The pretender himself has lauded President Franc ois Mitterrand, the Socialist president of France.

"Your birth gives you only one right," Henri told his grandson today. "That is to pursue the work undertaken for 1,000 years in the service of France and every one of its inhabitants.