Ever since he was a boy, Lee Hsien Loong knew he was destined for high office.
Lee Hsien Loong was in the army before entering politics at age 32
As the elder son of the founder of modern Singapore, Lee Kuan Yew, he grew up watching his father transform the city-state from a post-colonial backwater into South East Asia's richest nation.
Often criticised for being aloof and humourless, the younger Mr Lee has inherited his father's intellect and is seen as a safe pair of hands to take over as Singapore's third prime minister.
But many Singaporeans are anxious to know whether he will maintain the island's conservative status quo, or bring fresh faces into the government and release its tight grip on society.
Born in 1952, Lee Hsien Loong studied at Cambridge and Harvard, gaining a first-class degree in mathematics and a masters degree in public administration.
He then joined the military, quickly rising through the ranks to become brigadier-general.
In 1984, at the age of 32, he followed his father into politics as a member of the ruling People's Action Party.
Again he made rapid progress. He was elected to the party's Central Executive Committee in 1986, and was appointed deputy prime minister in November 1990.
Later he was also given the title of Minister for Finance and chairman of
the Monetary Authority of Singapore.
He played a key role in outgoing prime minister Goh Chok Tong's cabinet, and spearheaded many of the reforms aimed at re-igniting the economy.
Lee Kuan Yew will have a heavy influence on his son's leadership
But Mr Lee's rise to the top has not always been plain sailing. He has also faced tough personal challenges along the way.
His first wife died of a heart attack in 1982, shortly after giving birth to their second child.
He married businesswoman Ho Ching three years later, and has since had two more children.
Then, two years after his appointment as deputy prime minister, he was diagnosed with lymphoma.
Even this did not deter his ambition. When the cancer went into remission, he took on the extra roles of finance minister and central bank chairman.
He faces fresh challenges, too, in his role as prime minister. Jobs are disappearing, while Singapore's birth rate stagnates and its population ages.
Mr Lee also faces criticism over his family's virtual monopoly over Singapore's power structure.
The elder Mr Lee will still have an important role to play in government, as an officially appointed "minister mentor" to his son.
And the new prime minister's wife, Ho Ching, also holds considerable power as the executive director of a powerful government investment arm, Temasek Holdings.
Temasek owns stakes in Singapore Airlines and Singapore Telecommunications - whose chief executive is none other than Mr Lee's brother, Lee Hsien Yang.
But one of Lee Hsien Loong's most urgent challenges will be to act on the increasing calls for liberalisation.
Mr Lee's father may have built Singapore into a rich and prosperous nation, but in the process he imposed tight controls over everything from the freedom of the press to the chewing of gum.
Singaporeans want a change from what is often seen as an over-protective nanny state, and many hope a change of prime minister will bring a new era in personal freedom.
So far, however, Mr Lee looks set to keep the status quo largely intact. His chosen cabinet has few new faces, and he has not made any concrete announcements of change.
But in the past, Mr Lee has referred to the need for modernisation.
In a speech earlier this year to Singapore's influential Harvard Club, he said: "Whether it is a ceiling leak, a mosquito nuisance or a troublesome neighbour, usually the first question which people ask is: What will the government do about it? Nanny should not look after everything all the time."
It is time for the government to "cut the apron strings", he said.
As prime minister he has now got the power to do just that, if he chooses.