People in Japan expressed relief and happiness today after the birth of a baby boy to Princess Kiko.
Japanese Prince Akishino and his daughters, Princess Mako and Princess Kako arrive at Aiiku hospital in Tokyo today to see Princess Kiko and her new-born baby boy
The birth of the first male heir in the imperial family in more than four decades takes pressure off Crown Prince Naruhito and Crown Princess Masako to have a boy.
Their 4-year-old daughter Princess Aiko is not allowed to become sovereign under current law which limits the succession to males.
The baby prince becomes third in line to the throne after his uncle, the crown prince, and his father Prince Akishino.
The birth could scupper a plan to allow women ascend the throne, an idea opposed by traditionalists eager to preserve a practice they say stretches back more than 2,000 years.
The move also has popular support in the traditionally conservative country.
TV programmes flashed the news that a male heir had been born and newspapers issued extra editions.
Chief Cabinet Secretary Shinzo Abe, expected to become Japan's new prime minister this month, welcomed the birth.
"It's a refreshing feeling that reminds us of a clear autumn sky," he told reporters.
Asked about succession law reform, he added: "It is important for us to discuss it calmly, carefully and firmly."
An Imperial Household Agency official told reporters Kiko had given birth by a Caesarean operation weighing 5 lb 10 ounces just before midnight Irish time.
He said both Kiko (39) and the baby were doing well.