Hope flowers for the Chrysanthemum Throne after birth of a Japanese prince

One of the more colourful comments uttered after the birth of Japan's first male heir to the imperial throne in four decades came yesterday from the chief cabinet spokesman, Shinzo Abe, who described the news as "a refreshing feeling that reminds us of a clear autumn sky".

Mr Abe, who is widely expected to become Prime Minister later this month, had every reason to wax poetic. The baby boy saves imperial traditionalists like him from their worst fear: a female emperor.

The 5lb 6oz bundle delivered by Princess Kiko yesterday not only miraculously rescues the Imperial Family from a looming succession crisis, it effectively terminates a fractious debate on whether to allow women to warm the Chrysanthemum Throne.

That debate threatened "to split the government in two" if handled badly, said one minister this year.

Mr Abe gave a hint of the depth of feeling that talk of a female emperor inspires recently when he said that any discussion on revising the male-only law should proceed "in a careful and level-headed manner," because the family is related to the "basis of our nation".

Many believe the boy, who is third in line to the throne, will one day inherit a family crest that can trace its roots back more than 2,000 years. Even those who don't buy into the official line that the family has reigned "since time immemorial" believe it provides stability, continuity and tradition in a country that has been transformed beyond all recognition. A girl, so traditionalist thinking goes, might one day do the unthinkable: marry the wrong kind of man or, even worse, a foreigner.

The guardians of this tradition are the 1,100 bureaucrats of the Imperial Household Agency, the secretive government body that manages the life of the royals, along with the Shinto priests who oversee religious rites. It is these guardians - all men - who will guide the young heir through a life of elaborate ritual, which began yesterday with the presentation of a sword symbolising the protection of his grandfather, Emperor Akihito.

Next week, his father will choose his name and his mother his imperial symbol. Thereafter, his life will be ruled by an imperial template laid down hundreds of years ago, starting with his first official meeting with the Emperor in 50 days and his first feeding with chopsticks in 120.

Japan's royals endure most of the duties but few of the perks of monarchial life. The young boy will have virtually no independent wealth and no control over his life until he reaches maturity, and even then his schedule will be controlled by others. Eventually, like his father and uncle, he will face the excruciating search for a wife, and the intense media scrutiny that comes with it. Then his problems really start: producing a royal brood that will ensure the survival of the institution into the next century.

At least he will have a childhood: many of his ancestors ascended the throne when barely out of nappies and abdicated in their teens. And he will be raised mostly by his mother and father -- the first generation not to have been separated as a baby.

All eyes will now be on his aunt, Princess Masako, who struggled to produce a male heir for seven years before delivering Princess Aiko in 2001, sparking the succession crisis. She largely disappeared from official duties two years later, allegedly suffering from depression.

Will the new addition to the family ease the pressure, now that her daughter is removed from the spotlight?

"I think the question is this: does she dislike the whole environment of the Imperial Household now so much that she is relieved that her daughter might not have to live in that stifling environment?" said Ken Ruoff, author of The People's Emperor.

Or, will she decide that the 13 years she has carried the bane of two millenniums of imperial tradition has been for nothing? The most serious issue raised by yesterday's events, however, resonates far outside the Imperial Palace. With the new arrival, Japan has in all likelihood postponed any attempt to change the succession, making it unique among the dwindling band of constitutional monarchies. "For a country concerned about its image, you wonder what sort of message people are getting abroad - that there is this faction that is completely against change and that they're going to get away with this," Mr Ruoff said.

Ultimately, that decision means the task of reproducing this most venerable of institutions falls on the infant that wailed into life in a Tokyo hospital yesterday. Can he bear the load? It would be ironic indeed if, in trying to save the Imperial Family, they have ensured its extinction.