When Xi Jinping took power in 2012, some observers predicted he would be the most liberal Communist Party leader in China's history, based on his low-key profile, family backstory and perhaps a degree of misguided hope.

Ten years later, those forecasts lie in tatters, proving only how little was understood of the man who is now China's most powerful ruler since Mao Zedong.

The colourful details of his early life have been rinsed and repackaged in official party lore, but the man himself -- and what drives him -- remain somewhat more of an enigma.

"I dispute the conventional view that Xi Jinping struggles for power for power's sake," Alfred L. Chan, author of a book on Xi's life, told AFP. "I would suggest that he strives for power as an instrument... to fulfil his vision."

Another biographer, Adrian Geiges, told AFP that he did not think Xi was motivated by a desire for personal enrichment, despite international media investigations having revealed his family's amassed wealth.

"That's not his interest," Geiges said. "He really has a vision about China, he wants to see China as the most powerful country in the world."

Central to that vision -- what Xi calls the "Chinese Dream" or "great rejuvenation of the Chinese nation" -- is the role of the Communist Party (CCP).

"Xi is a man of faith... for him, God is the Communist Party," wrote Kerry Brown, author of "Xi: A Study in Power".

"Xi is a man of faith... for him, God is the Communist Party. The greatest mistake the rest of the world makes about Xi is to not take this faith seriously."

"The greatest mistake the rest of the world makes about Xi is to not take this faith seriously."

Xi might not seem an obvious candidate to become a CCP diehard, though he grew up as a "princeling", or member of the party elite.

His father Xi Zhongxun was a revolutionary hero turned vice premier, whose "strictness toward his family members was so serious that even those close to him believed it bordered on the inhuman", according to the elder Xi's biographer Joseph Torigian.

But when Xi Zhongxun was purged by Mao and targeted during the Cultural Revolution, "(Xi Jinping) and his family were traumatised", said Chan.

His status vanished overnight, and the family was split up. One of his half-sisters is reported to have killed herself because of the persecution.

At just 15, Xi was ordered to the countryside in central China where he spent years hauling grain and sleeping in cave homes.

"The intensity of the labour shocked me," he later said. He also had to take part in "struggle sessions" in which he had to denounce his father.

Biographer Chan said the experiences of his youth had given him "toughness" and the vents also made him realise the importance of  law-based governance.

His rise to the power was not simple.

His application for CCP membership was rejected multiple times because of the family stigma, before it was finally accepted.

And he rose one step at a time.

Beginning as a village party boss in 1974, Xi climbed to the governorship of coastal Fujian province in 1999, then party chief of Zhejiang province in 2002 and eventually Shanghai in 2007.

Xi's father was rehabilitated in the late 1970s following the death of Mao, massively boosting his son's standing.

Even so, his potential was not apparent to all, exemplified by comments made by his host on a trip to the United States in 1985.

"No one in their right mind would ever think that that guy who stayed in my house would become the president," Eleanor Dvorchak was quoted as saying years later in the New Yorker magazine.

But Xi has always regarded himself "as an heir of the revolution", said Chan.

In 2007, he was appointed to the Politburo Standing Committee, the party's highest decision-making body.

When he replaced Hu Jintao five years later, there was little in Xi's past administrative record that foreshadowed his actions once installed as leader.

"The absolute centrality of the party's mission to make China a great country again is evident from Xi's earliest recorded statements," wrote Brown.

Xi has harnessed that narrative of an ascendant China to great effect, using nationalism as a tool for his own and the party's legitimacy among the population.

But there is also evidence he fears that grasp on power might decline.

"The fall of the Soviet Union and of socialism in eastern Europe was a big shock," said Geiges, adding Xi blames the collapse on its political opening up.

"So he decided that something like this shall not happen to China... that's why he wants strong leadership of the Communist Party, with one strong leader."