After the death of premier Zhou Enlai in January, sparking a bitter power struggle in the Communist Party, on July 28 one of the century's worst natural disasters struck the northeastern city of Tangshan.
More than 250,000 people died and hundreds of thousands more were made homeless by an earthquake.
Mao, already on his sick bed, refused offers of international aid. China, he said, was strong enough to rescue itself.
To this day, many Chinese view the Tangshan earthquake and Mao's death only six weeks later as inextricably linked.
Over more than half a century, Mao's political manoeuvrings, personal ambitions and purges took China through a period of violent upheaval unprecedented in even that country's long and bloody history.
Born in 1893, the son of a wealthy Hunanese peasant family, Mao grew up in the dying days of imperial China.
Brought up as a Buddhist, he quickly turned to political radicalism, angry at what he saw as China's weakness in the face of foreign imperialism.
As a student in Beijing he encountered Marxism and in the early 1920s he became one of the founding members of the Communist Party of China (CPC).
Mao saw China's mainly peasant
population as ripe for revolution
He began to develop his theories of violent revolution, adapting the principles of Marxism to China, with its mainly peasant population.
From a small, poorly armed bunch, Mao's Red Army evolved into a determined guerrilla force numbering up to 200,000.
More than 20 years of civil war followed before Mao's forces overcame the Nationalist Kuomintang government of General Chiang Kai-Shek.
Meanwhile, throughout the conflict, Mao had also been fighting his own bloody war within the CPC.
Regular purges of those he saw as his opponents led to thousands of deaths – often made slow and agonising on Mao’s direct orders.
By the time he declared the founding of the People's Republic of China in 1949 he had, using his own brand of terror, firmly stamped his control on the CPC. Now he set out to make his mark on China itself.
From the early 1950s, Mao became fixated with the idea of China catching up with the West, industrially and militarily.
Friend and foe
Overtly Mao presented himself as an enemy of landowners, businessmen and foreign imperialists but a friend to poor peasants and workers.
Mao was determined to squash
Covertly he was determined to liquidate anyone who stood in his way.
In 1956 he and his premier, Zhou Enlai, initiated what became known as the "hundred flowers campaign", urging those with different opinions about how China should be governed to speak out.
Many thousands of Chinese intellectuals did just that.
But within two years the campaign had gone full circle. Those who had spoken out were branded rightists and counter-revolutionaries – effectively enemies of the state.
Many were executed, while others were forced from their jobs or humiliated and driven to suicide. Critics suggest that this had been Mao's aim all along – to lure his opponents into a trap.
Meanwhile, internationally China was becoming more and more isolated.
In Stalin's Soviet Union, Mao's China had had one solid ally. When Stalin died, the relationship quickly began to sour.
Determined that this would not derail China from his economic vision, Mao launched what he called the Great Leap Forward, a hare-brained effort to reorganise the Chinese peasantry into an industrial economy within five years.
The results were disastrous, decimating agricultural output and plunging much of the countryside into famine.
Estimates of the number of people who died vary between 18 and 43 million.
Forced to abandon the Great Leap in 1962, Mao was bruised but far from out. While other communist leaders sought to sideline him, Mao fought back.
Mao's Red Guards held him up as
a virtual living god
In 1966 he encouraged groups of young political radicals - to become known as the Red Guards - to stage The Great Proletarian Cultural Revolution.
Millions of young Chinese who had grown up knowing nothing but Mao took up the cause. Indoctrinated into the personality cult he had carefully crafted, Mao's word was akin to that of a god.
In the following decade China was to be plunged into another period of turmoil and bloodshed – as Mao fought to regain control of his party.
Hundreds of thousands were denounced at Red Guard show-trials, millions of lives were ruined, untold numbers were executed or worked to death.
China's rich cultural heritage was not spared either, much of which was destroyed or irreparably damaged for representing the hated "old ways of thinking".
By the early 1970s, poor health increasingly caught up with the ageing Mao.
In one of his last acts he oversaw a diplomatic rapprochement with the United States – which he saw as vital, if somewhat unpleasant, to counter China’s growing enmity with the Soviet Union.
Ultimately, bedridden and unseen in public for many months, Mao died shortly after midnight on September 9, 1976.
Thirty years on and China, politically and economically, has changed immeasurably.
Mao's mausoleum remains a
place of pilgrimage
From a drab, brow-beaten, Mao-suited nation, China has become an economic powerhouse with a rapidly growing entrepreneurial class and economic growth - in negative figures when Mao died - is the envy of the world.
Capitalists, once humiliated at mass rallies, are now welcomed into the ranks of the ruling Communist Party.
And yet China today remains very much stamped in the image of Mao.
Every year millions queue to view his embalmed corpse in its massive mausoleum on Tiananmen Square; or to visit his birthplace, Shaoshan, a carefully tended shrine to the cult of Mao.
Despite mounting evidence that he was responsible for the deaths of more people than Hitler, Stalin and Pol Pot combined, for China's rulers and many millions of Chinese today, Mao remains untouchable.