But it’s still a mistake to draw a straight line from Mao to Xi, Prof Karl argues, because it dismisses all that came in between – and the Chinese who dreamed or fought for a different country.

“It suggests autocracy is in their blood, it’s in their water or it’s in their culture,” she says.

The truth is Xi’s path to power was far from inevitable. And it’s defined as much by his ambition as it is by the party’s failure to prevent what they did not want – a repeat of Mao’s disastrous one-man rule.

“My first introduction to China was in the 1980s, when the debates about China’s future were huge, significant, and consequential,” Prof Karl says. “The party itself was involved in those debates. But 1989 shut that down.”

In 1989 – as the Soviet Union was breaking up – China’s hopes for change were crushed by tanks and automatic gunfire.

The country was still recovering in that decade or so following Mao’s death. Tens of millions had died on his watch – first from hunger because of his devastating mission to industrialise China overnight; and then in the violent, paranoid purges of rivals, dissidents, intellectuals and “class enemies”.

Mao’s mantle eventually fell to Deng Xiaoping, who had survived two purges, and insisted on collective leadership that would change every 10 years.

By 1989, that included General Secretary Zhao Ziyang, a reformist.

In the spring of that year hundreds of thousands of students and workers occupied central Beijing to protest against corruption and rising prices, and demand reform. Behind the high walls of the Communist Party’s leadership compound, Zhongnanhai, the party’s top rung split. Moderates led by Zhao tried to use the protests to push further reform. Hardliners, led by Premier Li Peng, believed the students’ goal was to overthrow the party, and wanted the protests quashed.

Zhao visited the protesters, urging them to call off their strike in what is now a historic speech: “We came too late. It’s right for you to talk about us and criticise us any way you want… We’re all old and it doesn’t matter to us anymore. But you’re still young, you should take care of yourself.”

At the end of May the hardliners won. Early on the morning of June 4, the tanks rolled in. The massacre at Tiananmen Square ended debate about political reform. Instead, the Communist Party turned to economic reform.

In 1992, Deng – who had remained China’s “paramount leader” – declared that the party should allow “some people to get rich first”.  It does not sound too dramatic, but it was another decisive break from Maoism. Revolutionary austerity had been shown the door.

On a chilly winter morning in January 1990, I stepped off a night ferry onto a dockside in the city of Guangzhou. It was my first glimpse of China. The air smelled sulphurous from burning coal. Outside the streets were a river of bicycles, ridden by workers in blue caps and Mao jackets. Occasionally the bicycles parted for a wheezing bus or official car.

Over the next six months I pedalled across the mountains of Yunnan, wandered the imperial palace in Beijing, and rode a train hauled by two soot-blackened steam engines far west into the deserts of Xinjiang. The landscapes were sublime but the poverty grinding. Everywhere I went people told me how “backward” China was compared to the West. But there were hints of change.

By the time I returned in 1998 the whole country had taken to heart Deng’s invocation “to get rich is glorious”. That year the Communist Party decreed China’s state-owned housing stock be sold off, lock, stock and barrel.  Swathes of Beijing’s historic grey-brick courtyards were being demolished and replaced with glass and steel.

The word on everyone’s lips was “xia hai” or “dive into the sea”. It meant quitting your old job in a state company and plunging into private business. I remember the day one of our assistants came into the BBC office, handed in his ID and declared, “I’m off to Shenzhen”, the boom city on China’s southern coast.

Mao had closed China’s economy off from the world. Now his successors were throwing it open. In 2001 China joined the World Trade Organisation. Along the southeast coast new cities mushroomed. Some specialised in buttons and zippers, others made cigarette lighters. In Zhejiang I found one that only made socks, tens of billions of them.

As I prepared to leave China in 2008, the Soviet-era airport had given way to a glittering megastructure designed by Norman Foster. And the first high-speed rail line opened between Beijing and Tianjin.

China was getting richer faster than any other country in history. But that unleashed other forces.

“Heaven is high and the emperor is far away” is an old, oft-quoted saying in China. It means there is no-one watching what you are doing.

That certainly seemed to be the case under Xi’s predecessor, Hu Jintao – corruption was on the rise and his authority was being openly ignored and even challenged.

As land prices shot up because of the reforms, party officials across China were confiscating property from peasant farmers, selling it to developers, and pocketing a hefty cut.

In 2005 I was handed a DVD smuggled out of a village called Dingzhou in Hebei province. It showed a pitched battle between local farmers and dozens of armed thugs, hired by a state-owned power company, to force them off their land. The farmers had dug deep trenches in their fields. The thugs attacked at dawn opening fire with shotguns and beating the farmers with steel bars. Six were killed.

The graft ran deep. In Beijing, I remember going to a nightclub whose owner was reputed to have a ready supply of illicit drugs and attractive young women for those with enough money. His business partner was the public security bureau – the police.

That was just the tip of an immense iceberg, says Richard McGregor, the former Beijing bureau chief for the Financial Times. “Everything and everybody got a cut, but it got out of control,” he adds. “It was becoming more like Suharto’s Indonesia, where it was corroding the foundations of the system.”

It was at this time – during a trade war between China and the EU over textile quotas – that I got a rare invitation to interview the commerce minister. Such interviews with top Chinese officials were excruciatingly dull, but this was the opposite.

The minister’s name was Bo Xilai. Tall, handsome and with a roguish charm, Bo seemed to enjoy the challenge, answering questions with wit and cogency. “This is a guy who could succeed as a politician anywhere,” I thought to myself.

In 2007 Bo was sent to run Chongqing, a vast city that straddles the Yangtze River in the mountains of southwest China. It was infamous then for organised crime.

Bo launched a ruthless anti-corruption campaign, netting hundreds of criminals, businessmen, politicians and police. He built lavish infrastructure, including public housing. Strangely he also revived “red culture”, requiring everyone to learn Mao-era songs praising the Communist Party. Many were terrorised by Bo’s rule, but he was wildly popular with the working class.

Politicians came from Beijing to study the “Chongqing model”. One of them was a rising star named Xi Jinping.

Then, in 2012, Bo, who had been building his own power base for years, was brought down by an extraordinary tale of murder, corruption and international intrigue that rocked China. Today he is serving life in prison.

His Chongqing model, however, was arguably the prototype for what Xi would soon unleash on the whole of China.

Xi was a princeling – the son of one of Mao’s lieutenants, Xi Zhongxun, who had been purged and later rehabilitated. Colleagues described the younger Xi as humble, self-disciplined and hardworking but otherwise unremarkable. Even on the eve of his elevation to general secretary of the Communist Party there was little hint of what was to come.

By the time Xi was appointed to lead the party in 2012, the corruption had reached its highest echelons. This terrified party elders who saw it as a grave threat, but also handed Xi an opportunity to pitch himself as a saviour.

“They thought it would last three to six months but it was never just an anti-corruption campaign, it was a party rectification campaign, and it was to be sustained forever,” says Professor Steve Tsang who heads the China Institute at the School of Oriental and African Studies in London.

Following Bo’s stunning fall, hundreds of thousands of party cadres were put under investigation. More than 100,000 were indicted for corruption, including 120 high-ranking officials. Corruption plummeted and Xi’s popularity soared.

Now he had the ammunition to destroy his most potent political rivals. He ordered the arrest of Zhou Yongkang in 2014, who until two years before had been a member of the politburo standing committee, and one of the most powerful men in China. Convicted in 2015, Zhou too is in prison for life.

This was unprecedented in the post-Mao era.

“I think the party elders must have had a touch of buyer’s remorse,” Mr McGregor says.

Xi’s ruthless and dramatic consolidation of power has caused many to liken him to Mao. But Mao’s destructiveness was rooted in his desire to build a socialist utopia. What does Xi want to build?

Nothing that Mao would recognise, Prof Karl says.

“China today has no socialist characteristics” she says “The subordination of labour to capital is complete. If you’re a real socialist, you must have a notion of class democracy, of justice, of hierarchy and anti-hierarchy. None of that is even part of Xi Jinping thought.”

The only thing that remains from Mao-era China is the party. And that, she says, is what Xi truly cares about.

“He believes that in the world of hyper-competitive capitalism and a hyper-competitive arms race with the United States, the only plausible way that China can remain competitive is to remain under one party that happens to be called the Communist Party.”

Nothing lends legitimacy to the Communist Party quite like Mao – the iconic revolutionary whose portrait still reigns over Tiananmen Square, where he declared the founding of the People’s Republic of China.

So his ruinous legacy was covered up with reverence. And now, Xi loses no opportunity to channel Mao, even usurping his defunct titles – Great Helmsman, People’s Leader, Chairman. But what he seeks is much bigger.

“The great emperors – that is who Xi actually looks up to, this guy is enormous in his ambition,” Prof Tsang says.

Xi’s goal, according to him, is a glorious mythical Chinese culture – tian xia or “all under heaven”. A unified China that is home to a unified people. “The Chinese patriot is somebody who loves China, the Communist Party and its leader,” Prof Tsang says. “And by Chinese he means Han culture.”

In Xi’s China there is almost no room for diversity. Xinjiang’s 12 million Uyghur Muslims are being forcibly assimilated. Similar programs are under way in Tibet and Inner Mongolia.

“The policies that Xi has applied – the re-education camps – it’s about making them more Chinese than Uyghur,” Mr McGregor says. “It’s cultural genocide.”

This is starkly different from Mao’s idea of a multi-ethnic state where, in theory, different groups had more autonomy. Xi’s father too had a reputation for conciliation and respect for China’s ethnic minorities.

But his son is driving a strident ethno-nationalism that seeks to unite the Chinese at home and drive away foreign powers who are, in Beijing’s view, trying to encircle and weaken China.

In November 2015, I took off from the Philippine Island of Palawan in a tiny single engine Cessna. Our destination was the Philippine-controlled atoll of Pagasa, 400 miles away in the middle of the South China Sea. Our plan was to pass close to a new Chinese military base, built on an artificial island atop “mischief reef”.

The outline of a runway and the extraordinary 9km long artificial island emerged as we approached.

Then, loudly over the radio, came a warning in Chinese and English: “Foreign military aircraft in northwest of Mischief Reef, this is the Chinese Navy! You are approaching Chinese airspace. To avoid further action, turn away and leave immediately!”

We were a civilian aircraft flying in international airspace. But that didn’t matter.

These South China Sea islands are only the most daring and visible of Xi’s moves to take control of the near abroad. Taiwan could be next.

“China is now doing all sorts of things that it’s always wanted to do but wasn’t powerful enough to do,” Mr McGregor says. “Taiwan was always there. The South China Sea was always there. Taking on America, driving it out of Asia was always an ambition, but they didn’t say it out loud.”

Now China is saying it out loud, and its “wolf warrior” diplomats, named after a patriotic action film franchise, are going on the verbal offensive. In China this is hugely popular.

But Xi’s policies are only creating the hostile world he claims he is defending against, believes Susan Shirk, a China expert in former US president Bill Clinton’s administration.

“Picking fights with your neighbours. Dusting off plans to build large artificial islands and fortify them with military installations. Ramping up the pressure on Japan and Taiwan. It’s a kind of self-encirclement that Chinese foreign policy has produced,” she says.

China’s brashness has been driven by its extraordinary power as both the world’s biggest factory and marketplace. It has so far seemed unstoppable, poised to unseat the US as the largest economy.

Then Covid threw a spanner in the works.

Earlier this year, a Chinese friend spent 83 days alone, locked in a Shanghai hotel room.

“It drives you crazy,” he says. “It’s a mixture of depression and anger. After a while you feel like you cannot breathe. Your body starts to shut down. Every day is the same. It’s like time has stopped.”

He got caught in China’s biggest and longest Covid lockdown. It was supposed to last four days, then another four, then another. Soon, the hotel staff stopped telling him.

“It’s amazing how China continues these lockdowns for so long – they are incredibly wrenching,” says Professor Dali Yan at Chicago University who has been studying the zero-Covid policy Xi has personally endorsed.

In the first year of Covid, Prof Yang says, the lockdowns made sense. They were brief and allowed life in China to carry on. There was even pride at how the country was handling the pandemic so much better than the West. “That’s no longer the case,” he says.

Economic growth has shrunk to 2%, the lowest in more than three decades. China’s property market is in free fall. Youth unemployment is running at around 20%. A trade war with the US is not helping. And anger has been brewing.

“Each night after midnight people would start sharing video clips on social media,” my Shanghai friend recalls. “They expressed their anger at the Communist Party, even at the very top leaders. They talked about how heartless and cruel this system has become.”

The video clips were quickly removed. The internet is instantly scrubbed of any signs of dissent or criticism, but the ire over zero-Covid has been palpable – even rare signs of protest have emerged, if only for moments, before they are silenced. It’s hard to deny that millions of Chinese hold Xi personally responsible for the cruelty of China’s grim lockdowns.

Fear and loyalty has led to “over-compliance and over-implementation of what Xi himself originally wanted”, Ms Shirk says.

And it appears to have paid off. Li Qiang, the Shanghai party chief who oversaw the city’s controversial shut down, has been elevated to premier, Xi’s second in command.

Behind the scripted scenes, China’s Communist Party hosts a cut-throat world. Surrounded by loyalists and with no heir in sight, Xi is now indisputably in command of a much wealthier country, with a vastly more powerful military. And for the first time, the world is uncertain of what to expect from China. Xi has swept aside the old guard, both the critical and the cautious.

“In the past, we could always count on China’s leaders to be pragmatic about economic policy, and prudent in their foreign policy. We don’t see that now,” Ms Shirk says.

Deng Xiaoping had famously said China should “hide its capacity and bide its time”.

That time has arrived.

In 2017, at the beginning of his second term, Xi declared: “China has stood up, grown rich, become strong and is moving towards the centre stage.”

He deliberately echoed Mao’s words in 1949 atop the Gate of Heavenly Peace in Tiananmen Square: “The Chinese People have stood up.”

But Xi’s China is not Mao’s China – and Xi’s ambition for himself and for his country far exceeds anything Mao ever dreamed of.

Mao, by all accounts, was a destroyer who ripped up the rule book not once but several times. But Xi is no anarchist – he is not even a rebel. And he certainly doesn’t want the chaos of Mao’s years, which tore apart his own family, to return.

What he does want is to be the most powerful leader China has ever had – and the Communist Party just handed him that victory.