PYONGYANG, North Korea (AP) ― His grandfather made his name in the 1930s as a teenage guerrilla, battling the Japanese soldiers who then occupied Korea. His father spent decades solidifying the family’s hold over the country, building up the military, extending the intelligence apparatus and driving its nuclear ambitions.

And Kim Jong-un himself? He apparently cut his teeth on the basketball courts of a Swiss middle school, a fiercely competitive player who posed as the son of a North Korean Embassy employee. Until, one day in 2000, he disappeared.

He wasn’t seen again publicly until 10 years later, when he stood near his ailing father, Kim Jong-il, at a Pyongyang military parade. Cheering crowds greeted the baby-faced “Young General’’ as North Korea’s ruler-in-waiting.

Now, with an outwardly seamless transition to the third generation of Kim family rulers, he appears to have been well-served by his competitive instincts.

In North Korea, everyone now knows who is in charge. Even if he probably isn’t yet 30.

Deafening cheers greeted Kim Jong-un when he stepped onto a viewing platform Sunday and waved to tens of thousands of soldiers and civilians gathered in Kim Il-sung Square, the huge plaza named for his grandfather and the heart of the North Korean capital.

“We have been transformed from a small and weak country ruthlessly trampled upon by competing powers into a confident political and military power,’’ Kim Jong-un said, the first time his voice had been heard here in public. “Our people are showing off their dignity as independent people who no one can dare provoke.’’

After Kim Jong-il’s death, many observers had predicted the son would be little more than a puppet guided by his father’s elderly inner circle.

But if it remains unclear exactly how much power Kim Jong-un wields, and how much he must share with the small coterie of relatives and advisers installed by his father, nearly all analysts say he has immense power.

In a week of events planned for the April 15 centenary of his grandfather’s birth, a day celebrated as one of the greatest in the country’s history, Kim assumed a series of top positions in the military, the ruling Workers’ Party and the government.

“It’s nonsensical to say somebody is pulling the strings behind Kim Jong-un,’’ said Cheong Seong-chang, a North Korea analyst at the private Sejong Institute near Seoul, South Korea.

While the government-controlled media carefully nurture comparisons to his grandfather, portraying him as a smiling everyman who meets everybody from the political elite to low-ranking soldiers, he also shares his father’s knack for confounding the U.S. and its allies.

Kim Jong-il was a master at using missile tests and nuclear research ― and then promises to scale them back ― to manipulate the West into providing humanitarian aid to the North.

The younger Kim, who is believed to be about 29 years old, is apparently doing the same thing, though analysts add that his long-term policies have not yet become clear. He faced a serious setback on Friday, when a rocket that North Korea said was carrying a satellite blew up shortly after liftoff, scattering pieces over the Yellow Sea.

Washington says the launch was a cover for testing ballistic missile technology, though North Korea says it simply wanted to put an observation satellite into space.

On Tuesday, North Korea’s Foreign Ministry rejected U.N. Security Council condemnation of the launch and accused the U.S. of leading a campaign to deny the country’s right to develop a civilian space program.

Kim’s speech two days after the launch may have overstated North Korea’s position in the world ― it remains a deeply impoverished nation, despite its nuclear and rocket research programs ― but it was also widely seen as a forceful statement about his control over North Korea. During his years in power, Kim Jong-il only spoke once publicly. And then very briefly.

Most of the basic facts about Kim Jong-un’s life, though, remain clouded.

North Koreans are told he graduated from Kim Il-sung Military University and speaks several foreign languages, including English. But his age, marital status and even the name of his late mother ― said to be one of Kim Jong-il’s wives, Ko Yong-hui ― have never been made public.

The little personal information to emerge about Kim comes mostly from former schoolmates in Switzerland, who in interviews with European news outlets remember him as a ferociously competitive basketball fanatic obsessed with Michael Jordan. For the most part, he kept his personal history a secret.