In the early hours of 4 June 1989, Li Rui, a veteran of the Chinese Communist party (CCP), was standing on the balcony of his apartment on Chang’an Boulevard in central Beijing. He could see tanks rolling towards Tiananmen Square.

For weeks, up to a million protesters had been gathering peacefully in Beijing’s plaza, demanding political reform. But they failed. Instead, as Li observed from his unique vantage point, troops opened fire, killing an estimated several thousands of civilians. It was the worst massacre in recent Chinese history. “Soldiers firing randomly with their machine guns, sometimes shooting the ground and sometimes shooting toward the sky,” Li wrote in his diary. A “black weekend”.

The first-hand account of an event that the Chinese government has systematically tried to distort and erase from the historical record is one of thousands of observations noted in Li’s diaries, which he kept meticulously between 1938 and 2018. Few people, especially not of Li’s stature, have kept such detailed records of this tumultuous era in Chinese history. Now those diaries are the subject of a hotly disputed lawsuit, the trial of which begins on Monday.

Born in 1917, Li joined the Com­munist party as a young idealist. After the communists seized power in 1949, he rose through the ranks to become Mao’s personal secretary in 1958. But it wasn’t to last. Amid the turmoil of the Cultural Revolution, Li was subjected to political persecution, including more than eight years in solitary confinement. It wasn’t until Mao died in 1976 that Li returned to the senior party ranks. He went on to become one of the most outspoken members of the liberal, reformist faction, observing from the inside the silencing of dissent that has intensified under the rule of his personal acquaintance Xi Jinping.

Li’s papers are, therefore, thus a crucial archive. “It’s hard to overstate their significance,” says Joseph Torigian, a research fellow at Stanford University’s Hoover Institution. But on Monday, a court in California, not China, will begin hearing a trial about the fate of those diaries, the culmination of five years of legal wrangling that have complicated Li’s legacy since he died in February 2019, at the age of 101.

For several years before his death, Li’s daughter Li Nanyang, who lives in the US, had been scanning, transcribing and cataloguing her father’s papers, and ultimately transferred them to the Hoover Institution, the leading archive for CCP history in the US. Li Nanyang and Stanford claim that this was in line with Li’s wishes. On 30 January 2017, for example, he recorded a meeting with his wife, Zhang Yuzhen, to talk about “the issue of my diaries”. Zhang “agreed with my decision … having Hoover retain the diaries”, he wrote.

But on 21 March 2019, a lawyer for Li’s widow wrote to Stanford, asserting her ownership of the diaries and seeking their return. The 89-year-old soon filed a lawsuit in Beijing, arguing that she was the rightful heir to Li’s estate. In May that year, Stanford filed a countersuit in California to eliminate Zhang’s claims to the materials. And so began a legal battle between one of the world’s top universities and an ageing widow – who, Stanford argues, is a front for the Chinese government.

Why would Zhang, who is now well into her 90s, spend several years and millions of dollars fighting over a collection of diaries?

Lawyers for Zhang, who did not respond to interview requests, say it is about privacy. The materials reflect “deeply personal” affairs, including “intimate correspondence”, her lawyers argue. The “ongoing violations” of her privacy have caused “severe emotional distress”.

But others are sceptical. “By all indications … the PRC [People’s Republic of China] is running this litigation behind the scenes,” lawyers for Stanford have argued. “To put it simply, Ms Zhang lacks the financial ability to pay the attorneys’ fees being incurred on her behalf.” Zhang’s lawyers deny there has been any interference from the Chinese government.

“It’s simply about control,” says Ian Johnson, author of a book about China’s unofficial historians, such as Li. Under Xi Jinping, China’s leader, the party has made it clear that it “can’t allow competing narratives of what happened in the past”.

In many countries, the diaries of a political leader would be housed in an archive, available to researchers or the public. In China, the opposite is true. In 2013, Xi warned against “historical nihilism”. For historians, that has meant that, after a period of relative openness, archive after archive has been shuttered. In 2012, the archives of the foreign ministry

abruptly closed, reopening the following year with 90% of the materials redacted.

That makes Li’s diaries particularly valuable to researchers. “The detail is mind-boggling,” says Frank Dikötter, a historian. Insights into elite politics are buried among notes about how many laps he swam in the pool, and how many times he got up to use the bathroom at night. Domestic details ­notwithstanding, Dikötter says it’s unimaginable that his diaries could be displayed in today’s China. “When you have a monopoly over power, you develop an obsession with secrecy.”

Li was keenly aware of this trend. In 2013, he said in an interview: “There are classified materials of the party about the Cultural Revolution … I heard it was all burned.” Such titbits have been marshalled by Stanford to argue that Li wanted his papers preserved at Hoover. But Zhang’s lawyers have found their own bits of evidence in Li’s voluminous writings and interviews. In 2014, he said, “Li Nanyang is Li Nanyang, and I am myself. My thoughts and opinions are well known and expressed in my books and articles. Li Nanyang is my daughter, but she can’t represent me, and I don’t allow her to represent me.”

Li Nanyang, a fierce CCP critic herself, doesn’t dispute the fact that she and her father didn’t always see eye to eye. “He wanted to save the party. That’s not my idea … This is not something that demonstrates that my father won’t work with me [to donate] his historical materials.”

Zhang denies that there is a plot to hide the Li Rui diaries from the public. Her legal filings note that she is only seeking the return of his original handwritten diaries, not the full collection of papers at Hoover, and that Hoover is free to make copies for researchers.

But historians say that original manuscripts are vital, especially when history is contested. It’s “crucial that you have the hand­written ones,” says Dikötter. “Because, ultimately, that’s what the whole thing relies on. The credibility relies on that.”

Li “would have known how difficult it would have been for [the diaries] to see the light of day [in China],” says Johnson. “I think very much that he wanted to donate them to Hoover.”

Li died without a will. His daughter says that this is because if he had made his intention public, including getting a will formally notarised, he would have faced trouble from the government. Zhang’s lawyers have quoted from a draft will, in which Li stated that his children “must not participate in the publication of my diaries”. Stanford says it has never seen evidence of this draft.

A court in Beijing long ago ruled in Zhang’s favour. A second lawsuit filed in Beijing by Li Nanyang’s sister, seeking the return of the papers relating to their mother, Li Rui’s first wife, also resulted in a judgment that the materials should be returned. But the 40 boxes full of pages and pages of Li’s dense scrawl, documenting the dramatic and often darkening developments of China in the 20th century, for now remain at Stanford. Some legal experts have pointed out that this week’s trial could simply be a question of whether a US court should respect a ruling made in a foreign jurisdiction. But for scholars, the stakes are higher. The ­diaries are “a monument to history”, says Dikötter.