In anticipation of New Year’s Eve, 2014, Xi Jinping, the President of China and the General Secretary of the Chinese Communist Party, permitted a camera crew to come into his office and record a message to the people. As a teen-ager, Xi had been sent to work on a farm; he was so delicate that other laborers rated him a six on a ten-point scale, “not even as high as the women,” he said later, with some embarrassment. Now, at sixty-one, Xi was five feet eleven, taller than any Chinese leader in nearly four decades, with a rich baritone and a confident heft. When he received a guest, he stood still, long arms slack, hair pomaded, a portrait of take-it-or-leave-it composure that induced his visitor to cross the room in pursuit of a handshake.

Xi’s predecessor, Hu Jintao, read his annual New Year’s greeting from a lectern in an antiseptic reception hall. Xi, who took office in November, 2012, has associated himself with an earthier generation of Communists, a military caste that emphasized “hard work and plain living.” He delivered his New Year’s message at his desk. Behind him, bookshelves held photographs that depicted him as Commander-in-Chief and family man. In one picture, he was wearing Army fatigues and a fur hat, visiting soldiers in a snowfield; in another, he was strolling with his wife and daughter, and escorting his father, Xi Zhongxun, a hallowed revolutionary, in a wheelchair. The shelves also held matching sets of books. Xi’s classroom education was interrupted for nearly a decade by the Cultural Revolution, and he has the autodidact’s habit of announcing his literary credentials. He often quotes from Chinese classics, and in an interview with the Russian press last year he volunteered that he had read Krylov, Pushkin, Gogol, Lermontov, Turgenev, Dostoyevsky, Nekrasov, Chernyshevsky, Tolstoy, Chekhov, and Sholokhov. When he visited France, he mentioned that he had read Montesquieu, Voltaire, Rousseau, Diderot, Saint-Simon, Fourier, Sartre, and twelve others. In his New Year’s remarks, Xi oscillated between socialist slogans (“Wave high the sword against corruption”) and catchphrases from Chinese social media (“I would like to click the thumbs-up button for our great people”). He vowed to fight poverty, improve the rule of law, and hold fast to history. When he listed the achievements of the past year, he praised the creation of a holiday dedicated to the Second World War: “Victory Day of the Chinese People’s War of Resistance Against Japanese Aggression.”

Xi is the sixth man to rule the People’s Republic of China, and the first who was born after the revolution, in 1949. He sits atop a pyramid of eighty-seven million members of the Communist Party, an organization larger than the population of Germany. The Party no longer reaches into every corner of Chinese life, as it did in the nineteen-seventies, but Xi nevertheless presides over an economy that, by one measure, recently surpassed the American economy in size; he holds ultimate authority over every general, judge, editor, and state-company C.E.O. As Lenin ordained, in 1902, “For the center . . . to actually direct the orchestra, it needs to know who plays violin and where, who plays a false note and why.”

Xi’s New Year’s message was broadcast on state television and radio channels at 6:30 P.M., just before the evening news. A few hours later, the news veered sharply out of his control. In Shanghai, a large holiday crowd had gathered to celebrate on the Bund, the promenade beside the Huangpu River, with splendid views of the skyline. The crowd was growing faster than the space could handle. Around 11:30 P.M., the police sent hundreds of extra officers to keep order, but it was too late; a stairway was jammed, and people shouted and pushed. A stampede ensued. In all, thirty-six people suffocated or were trampled to death.

The disaster occurred in one of China’s most modern and prosperous places, and the public was appalled. In the days that followed, the Shanghai government held a memorial for the victims, and encouraged people to move on; Internet censors struck down discussion of who was responsible; police interrogated Web users who posted criticisms of the state. When relatives of the victims visited the site of the stampede, police watched them closely, and then erected metal barriers to render it unreachable. Caixin, an investigative media organization, revealed that, during the stampede, local officials in charge of the neighborhood were enjoying a banquet of sushi and sake, at the government’s expense, in a private room at the Empty Cicada, a luxury restaurant nearby. This was awkward news, because one of the President’s first diktats had been “Eight Rules” for public servants, to eliminate extravagance and corruption. Among other things, the campaign called on officials to confine themselves to “four dishes and one soup.” (Eventually, eleven officials were punished for misusing funds and for failing to prevent a risk to the public.)

A few weeks after the incident in Shanghai, I paid a call on a longtime editor in Beijing, whose job gives him a view into the workings of the Party. When I arrived at his apartment, his kids were in raucous control of the living room, so we retreated to his bedroom to talk. When I asked him how President Xi was doing, he mentioned the banquet at the Empty Cicada. He thought it pointed to a problem that is much deeper than a few high-living bureaucrats. “The central government issued an order absolutely forbidding them to dine out on public funds. And they did it anyway!” he said. “What this tells you is that local officials are finding their ways of responding to change. There is a saying: ‘When a rule is imposed up high, there is a way to get around it below.’ ” The struggle between an emperor and his bureaucracy follows a classic pattern in Chinese politics, and it rarely ends well for the emperor. But the editor was betting on Xi. “He’s not afraid of Heaven or Earth. And he is, as we say, round on the outside and square on the inside; he looks flexible, but inside he is very hard.”

Before Xi took power, he was described, in China and abroad, as an unremarkable provincial administrator, a fan of American pop culture (“The Godfather,” “Saving Private Ryan”) who cared more about business than about politics, and was selected mainly because he had alienated fewer peers than his competitors. It was an incomplete portrait. He had spent more than three decades in public life, but Chinese politics had exposed him to limited scrutiny. At a press conference, a local reporter once asked Xi to rate his performance: “Would you give yourself a score of a hundred—or a score of ninety?” (Neither, Xi said; a high number would look “boastful,” and a low number would reflect “low self-esteem.”)

But, a quarter of the way through his ten-year term, he has emerged as the most authoritarian leader since Chairman Mao. In the name of protection and purity, he has investigated tens of thousands of his countrymen, on charges ranging from corruption to leaking state secrets and inciting the overthrow of the state. He has acquired or created ten titles for himself, including not only head of state and head of the military but also leader of the Party’s most powerful committees—on foreign policy, Taiwan, and the economy. He has installed himself as the head of new bodies overseeing the Internet, government restructuring, national security, and military reform, and he has effectively taken over the courts, the police, and the secret police. “He’s at the center of everything,” Gary Locke, the former American Ambassador to Beijing, told me.

In the Chinese Communist Party, you campaign after you get the job, not before, and in building public support and honing a message Xi has revealed a powerful desire for transformation. He calls on China to pursue the Chinese Dream: the “great rejuvenation of the nation,” a mixture of prosperity, unity, and strength. He has proposed at least sixty social and economic changes, ranging from relaxing the one-child policy to eliminating camps for “reëducation through labor” and curtailing state monopolies. He has sought prestige abroad; on his first foreign trip (to Moscow), he was accompanied by his wife, a celebrity soprano named Peng Liyuan, who inspired lavish coverage of China’s first modern Presidential couple. Peng soon appeared on Vanity Fair’s Best-Dressed List.

After Mao, China encouraged the image of a “collective Presidency” over the importance of individual leaders. Xi has revised that approach, and his government, using old and new tools, has enlarged his image. In the spirit of Mao’s Little Red Book, publishers have produced eight volumes of Xi’s speeches and writings; the most recent, titled “The Remarks of Xi Jinping,” dissects his utterances, ranks his favorite phrases, and explains his cultural references. A study of the People’s Daily found that, by his second anniversary in office, Xi was appearing in the paper more than twice as often as his predecessor at the same point. He stars in a series of cartoons aimed at young people, beginning with “How to Make a Leader,” which describes him, despite his family pedigree, as a symbol of meritocracy—“one of the secrets of the China miracle.” The state news agency has taken the unprecedented step of adopting a nickname for the General Secretary: Xi Dada—roughly, Big Uncle Xi. In January, the Ministry of Defense released oil paintings depicting him in heroic poses; thousands of art students applying to the Beijing University of Technology had been judged on their ability to sketch his likeness. The BeijingEvening News reported that one applicant admired the President so much that “she had to work hard to stop her hands from trembling.”

To outsiders, Xi has been a fitful subject. Bookstores in Hong Kong, which are insulated from mainland control, offer portraits of varying quality—the most reliable include “The New Biography of Xi Jinping,” by Liang Jian, and “China’s Future,” by Wu Ming—but most are written at a remove, under pseudonyms. The clearest account of Xi’s life and influences comes from his own words and decisions, scattered throughout a long climb to power.

Kevin Rudd, the former Prime Minister of Australia, a Mandarin speaker who has talked with Xi at length over the years, told me, “What he says is what he thinks. My experience of him is that there’s not a lot of artifice.”

In a leadership known for grooming colorless apparatchiks, Xi projects an image of manly vigor. He mocks “eggheads” and praises the “team spirit of a group of dogs eating a lion.” In a meeting in March, 2013, he told the Russian President, Vladimir Putin, “We are similar in character,” though Xi is less inclined toward bare-chested machismo. Xi admires Song Jiang, a fictional outlaw from “Water Margin,” a fourteenth-century Chinese classic, for his ability to “unite capable people.” Neither brilliant nor handsome, Song Jiang led a band of heroic rebels. In a famous passage, he speaks of the Xunyang River: “I shall have my revenge some day / And dye red with blood the Xunyang’s flow.”

Xi describes his essential project as a rescue: he must save the People’s Republic and the Communist Party before they are swamped by corruption; environmental pollution; unrest in Hong Kong, Xinjiang, and other regions; and the pressures imposed by an economy that is growing more slowly than at any time since 1990 (though still at about seven per cent, the fastest pace of any major country). “The tasks our Party faces in reform, development, and stability are more onerous than ever, and the conflicts, dangers, and challenges are more numerous than ever,” Xi told the Politburo, in October. In 2014, the government arrested nearly a thousand members of civil society, more than in any year since the mid-nineteen-nineties, following the Tiananmen Square massacre, according to Chinese Human Rights Defenders, a Hong Kong-based advocacy group.

Xi unambiguously opposes American democratic notions. In 2011 and 2012, he spent several days with Vice-President Joe Biden, his official counterpart at the time, in China and the United States. Biden told me that Xi asked him why the U.S. put “so much emphasis on human rights.” Biden replied to Xi, “No President of the United States could represent the United States were he not committed to human rights,” and went on, “If you don’t understand this, you can’t deal with us. President Barack Obama would not be able to stay in power if he did not speak of it. So look at it as a political imperative. It doesn’t make us better or worse. It’s who we are. You make your decisions. We’ll make ours.”

In Xi’s early months, supporters in the West speculated that he wanted to silence hard-line critics, and would open up later, perhaps in his second term, which begins in 2017. That view has largely disappeared. Henry Paulson, the former Treasury Secretary, whose upcoming book, “Dealing with China,” describes a decade of contact with Xi, told me, “He has been very forthright and candid—privately and publicly—about the fact that the Chinese are rejecting Western values and multiparty democracy.” He added, “To Westerners, it seems very incongruous to be, on the one hand, so committed to fostering more competition and market-driven flexibility in the economy and, on the other hand, to be seeking more control in the political sphere, the media, and the Internet. But that’s the key: he sees a strong Party as essential to stability, and the only institution that’s strong enough to help him accomplish his other goals.”

In his determination to gain control and protect the Party, Xi may have generated a different kind of threat: he has pried apart internal fault lines and shaken the equilibrium that for a generation marked the nation’s rise. Before Xi took power, top officials presumed that they were protected. Yu Hua, the novelist, told me, “As China grew, what really came to matter were the ‘unwritten rules.’ When the real rules weren’t specific enough or clear enough, when policies and laws lagged behind reality, you always relied on the unwritten rules.” They dictated everything from how much to tip a surgeon to how far an N.G.O. could go before it was suppressed. “The unwritten rules have been broken,” Yu said. “This is how it should be, of course, but laws haven’t arrived yet.”

The Communist Party dedicated itself to a classless society but organized itself in a rigid hierarchy, and Xi started life near the top. He was born in Beijing in 1953, the third of four children. His father, Xi Zhongxun, China’s propaganda minister at the time, had been fomenting revolution since the age of fourteen, when he and his classmates tried to poison a teacher whom they considered a counterrevolutionary. He was sent to jail, where he joined the Communist Party, and eventually he became a high-ranking commander, which plunged him into the Party’s internal feuds. In 1935, a rival faction accused Xi of disloyalty and ordered him to be buried alive, but Mao defused the crisis. At a Party meeting in February, 1952, Mao stated that the “suppression of counterrevolutionaries” required, on average, the execution of one person for every one thousand to two thousand citizens. Xi Zhongxun endorsed “severe suppression and punishment,” but in his area “killing was relatively lower,” according to his official biography.

Xi Jinping grew up with his father’s stories. “He talked about how he joined the revolution, and he’d say, ‘You will certainly make revolution in the future,’ ” Xi recalled in a 2004 interview with the Xi’an Evening News, a state-run paper. “He’d explain what revolution is. We heard so much of this that our ears got calluses.” In six decades of politics, his father had seen or deployed every tactic. At dinner with the elder Xi in 1980, David Lampton, a China specialist at the School of Advanced International Studies at Johns Hopkins, marvelled that he could toast dozens of guests, over glasses of Maotai, with no visible effects. “It became apparent that he was drinking water,” Lampton said.

When Xi Jinping was five, his father was promoted to Vice-Premier, and the son often visited him at Zhongnanhai, the secluded compound for top leaders. Xi was admitted to the exclusive August 1st School, named for the date of a famous Communist victory. The school, which occupied the former palace of a Qing Dynasty prince, was nicknamed the lingxiu yaolan—the “cradle of leaders.” The students formed a small, close-knit élite; they lived in the same compounds, summered at the same retreats, and shared a sense of noblesse oblige. For centuries before the People’s Republic, an evolving list of élite clans combined wealth and politics. Some sons handled business; others pursued high office. Winners changed over time, and, when Communist leaders prevailed, in 1949, they acquired the mantle. “The common language used to describe this was that they had ‘won over tianxia’—‘all under Heaven,’ ” Yang Guobin, a sociologist at the University of Pennsylvania, told me. “They believed they had a natural claim to leadership. They owned it. And their children thought, naturally, they themselves would be, and should be, the future owners.” As the historian Mi Hedu observes in his 1993 book, “The Red Guard Generation,” students at the August 1st School “compared one another on the basis of whose father had a higher rank, whose father rode in a better car. Some would say, ‘Obey whoever’s father has the highest position.’ ” When the Cultural Revolution began, in 1966, Beijing students who were zilaihong (“born red”) promoted a slogan: “If the father is a hero, the son is also a hero; if the father is a reactionary, the son is a bastard.” Red Guards sought to cleanse the capital of opposition, to make it “as pure and clean as crystal,” they said. From late August to late September, 1966, nearly two thousand people were killed in Beijing, and at least forty-nine hundred historical sites were damaged or destroyed, according to Yiching Wu, the author of “The Cultural Revolution at the Margins.”

But Xi Jinping did not fit cleanly into the role of either aggressor or victim. In 1962, his father was accused of supporting a novel that Mao opposed, and was sent to work in a factory; his mother, Qi Xin, was assigned to hard labor on a farm. In January, 1967, after Mao encouraged students to target “class enemies,” a group of young people dragged Xi Zhongxun before a crowd. Among other charges, he was accused of having gazed at West Berlin through binoculars during a visit to East Germany years earlier. He was detained in a military garrison, where he passed the years by walking in circles, he said later—ten thousand laps, and then ten thousand walking backward. The son was too young to be an official Red Guard, and his father’s status made him undesirable. Moreover, being born red was becoming a liability. Élite academies were accused of being xiao baota—“little treasure pagodas”—and shut down. Xi and the sons of other targeted officials stayed together, getting into street fights and swiping books from shuttered libraries. Later, Xi described that period as a dystopian collapse of control. He was detained “three or four times” by groups of Red Guards, and forced to denounce his father. In 2000, he told the journalist Yang Xiaohuai about being captured by a group loyal to the wife of the head of China’s secret police:

I was only fourteen. The Red Guards asked, “How serious do you yourself think your crimes are?”

“You can estimate it yourselves. Is it enough to execute me?”