Japan's Crown Princess Masako gave birth Saturday to a daughter. The birth of a girl raises the possibility of a succession crisis for the world's oldest hereditary monarchy.

A top official of Japan's Imperial Household Agency announced Saturday that both mother and daughter are well, following the baby's birth at 2:43 p.m. local time.

When the announcement was made, crowds of Japanese surrounding the gates of Tokyo's Imperial Palace cheered and clapped. Some of the royal watchers were holding dogs, which are traditionally associated with a safe and easy birth.

The baby's first days will be steeped in tradition including the presentation to the newborn of a samurai sword by an imperial courtier. The baby's first bath was to be an ancient purification ritual, with musicians serenading outside the bathhouse.

And in keeping with ancient rules, the child's name will not be chosen by the parents, but by the grandfather, Emperor Akihito.

Many Japanese had hoped that 37-year-old Princess Masako, a former diplomat who speaks several languages, would bear a male child in order to avoid a succession crisis.

Japanese constitutional law reserves the throne for men. However, the last male heir to Japan's Chrysanthemum Throne was born in 1965. He is Prince Akishino, the younger brother of Crown Prince Naruhito. The last seven births in the royal family have all been girls.

Because of the lack of potential heirs after Prince Naruhito, some in Japan would like to see a revision of the law so that women, too, can also ascend the throne. The government says it has no plans to change the law, but Japanese historians say it could well be amended in the future.

Many Japanese revere the imperial family, but Princess Masako's pregnancy was virtually ignored by the public and the media. The Princess had a miscarriage two years ago, which the Imperial Household Agency blamed on stress caused by frenzied media coverage.