NEW YORK (AP) — Former United States President Donald Trump has testified in court as a football owner, casino builder and airline buyer. He bragged in a deposition that he saved “millions of lives” by deterring nuclear war as president. Another time, he fretted about the dangers of flung fruit.

Conditioned by decades of trials and legal disputes, Trump is now poised to reprise his role as witness under extraordinary circumstances: as a former Republican president fighting to save the real estate empire that vaulted him to stardom and the White House.

Trump is set to testify Monday at his New York civil fraud trial, taking the stand in a deeply personal matter that is central to his image as a successful businessman and threatens to cost him control of marquee properties such as Trump Tower. His highly anticipated testimony in the trial of New York Attorney General Letitia James’ lawsuit follows that of his eldest sons, Trump Organization executives Eric and Donald Trump Jr, who testified last week. His eldest daughter, Ivanka, is set to testify on Wednesday.

READ: Donald Trump set to take the stand in New York civil fraud trial

As court ended Friday, a state lawyer teased the former president’s appearance. Asked who would be testifying Monday, Andrew Amer told the judge: “The only witness will be Donald J Trump.”

Trump has testified in court in at least eight trials since 1986, according to an Associated Press review of court records and news coverage. He also has been questioned under oath in more than a dozen depositions and regulatory hearings.

In 1985, he was called to testify before Congress as owner of the USFL’s New Jersey Generals and he testified on behalf of lawyer and friend Roy Cohn at a state disciplinary hearing that led to Cohn’s disbarment. In an early flash of his firebrand persona, in 1986, Trump told New Jersey’s casino commission that plans for highway overpasses near one of his casinos “would be a disaster. It would be a catastrophe.”

Those testimonies, captured in thousands of pages of transcripts and some on videotape, offer clues to the approach Trump is likely to take when he testifies in Manhattan.

They show clear parallels between Trump as a witness and Trump as a president and current candidate for the office. His rhetorical style in legal proceedings over the years bears echoes of his political verve: a mix of ego, charm, defensiveness, aggressiveness, sharp language and deflection. He has been combative and boastful, but sometimes vague and prone to hedging or being dismissive.

Testifying in the USFL’s antitrust lawsuit against the NFL in 1986, Trump denounced allegations that he had spied on NFL officials at one of his hotels, calling the claim “such a false interpretation it’s disgusting.”

In 1988, as he sought to buy Eastern Air Lines’ Northeast shuttle service, Trump turned on the charisma, flashing a wide smile at the judge’s female law clerks and shaking hands with the bailiff during a break in his testimony at a federal court hearing in Washington. Trump testified that his $365 million purchase, later approved, would be a “major boost in morale” for employees.

On the stand in a boxing-related case in 1990, Trump described a Mike Tyson fight he planned for one of his casinos in Atlantic City, New Jersey, as “one of the greatest rematches you could have.” Accused by two men of cutting them out of a riverboat gambling project, Trump professed ignorance, testifying in 1999: “I was shocked by this whole case. I had no idea who these people were.”

Trump was briefly called to the witness stand in the New York case last month to explain comments outside of court that the judge said violated a limited gag order.

Before that, he last testified in a courtroom in 2013, two years before launching his winning presidential campaign. An 87-year-old suburban Chicago widower had sued him over changes to contract terms for a hotel and condominium tower she had bought units in as an investment. Trump grew increasingly agitated as his testimony wore on, at one point raising his arms and bellowing: “And then she sued me. It’s unbelievable!”

Chicago lawyer Shelly Kulwin cross-examined Trump on behalf of the plaintiff, Jacqueline Goldberg. He said the tenor of Trump’s testimony inside the federal courthouse in Chicago echoed the bruising ebb and flow later seen at campaign rallies and on TV.

“His demeanour was calm at first, and then argumentative, defensive, off-topic, speechmaking. Exactly what he does today,” Kulwin said in an interview.

“Based on my experience with him, you better be able to have super tight questions, with documents to support them, so that he cannot wiggle around,” Kulwin added. “I would approach the judge and have him admonished before he even got on the stand: ‘Mr Trump, this is not a political campaign. These people, you’re not trying to get their vote. This is a judicial proceeding.’”

Goldberg lost to Trump but said she did not regret suing him, testifying: “Somebody had to stand up to him.” She died in August at age 97.

Trump has attended seven days of the New York trial, quietly studying witnesses from the defence table while also lashing out at the case, the judge and state lawyers in front of TV cameras in the hallway. He called the case a “sham,” a “scam,” and “a continuation of the single greatest witch hunt of all time.”

Opining about the case on social media, he thrills in what he calls the trial’s “Perry Mason” moments — testimony and arguments he feels have helped his side — as he pays homage to the classic TV courtroom drama.

In 1990, Trump testified in a losing effort in a lawsuit over his company’s failure to make pension contributions on behalf of about 200 undocumented Polish workers hired to tear down a building to make way for Trump Tower. A year later, he was in court again in Manhattan, testifying against a man who claimed he had a contract to develop Trump’s board game and was owed 25 per cent of profits from “Trump: The Game.”

Trump won that one and another lawsuit in 2005, where he testified that a construction company had “fleeced” him by overcharging him by $1.5 million for work at a golf course in New York’s Westchester County.