He was belligerent and brash, unrepentant and verbose — regardless of the courtroom setting, he was the quintessential Donald J. Trump.
Within minutes of Mr. Trump’s taking the witness stand on Monday, his civil fraud trial in Manhattan devolved into a chaotic spectacle before a packed house. The former president lashed out at his accusers and denied their claims, even while conceding involvement in some of the conduct at the case’s heart.
Ranting and rambling as the courtroom pulsed with tension, Mr. Trump attacked New York’s attorney general, Letitia James, as a “political hack.” He derided the proceeding as “a very unfair trial.” And he scolded the judge overseeing the case, Arthur F. Engoron, for having decided before the trial that he had committed fraud.
“He called me a fraud, and he didn’t know anything about me!” Mr. Trump exclaimed from the stand, pointing at the judge, who flashed a grin.
The outbursts demonstrated the former president’s disdain for a case that has already imperiled his family business and labeled him a fraud and a cheat. Ms. James, who has become one of Mr. Trump’s arch antagonists, has not only put his company on trial, but also called into question the richer-than-rich persona that he built over his years as a businessman and reality television star — the identity that propelled his run for the White House.
Mr. Trump, who was accused by Ms. James of inflating his net worth to defraud banks and insurers, acknowledged helping to assemble annual financial statements submitted to the banks.
“I would look at them, I would see them, and I would maybe on occasion have some suggestions,” said Mr. Trump, who began the day looking tired but soon grew animated.
Although the admission appeared to bolster the attorney general’s case, Mr. Trump, seated 30 feet from Ms. James, also sought to minimize the import of the financial statements, which he said he largely left to aides. He noted that they contained numerous disclaimers, making them essentially “worthless.” Banks paid little attention to them, he said, before promising, unprompted, that some of his bankers would soon testify in his defense.
Mr. Trump, the leading Republican contender for the presidency, brought combative campaign-trail energy to the courtroom, punctuating his testimony with grandiose claims and long-winded asides that infuriated the judge and obscured some of his more effective testimony.
He delivered an impassioned ode to his golf course near Aberdeen, Scotland, calling it an “artistic expression” and the greatest ever built. He assailed Justice Engoron: “The fraud is on the court, not me.”
The judge, who will determine the outcome of the case instead of a jury, repeatedly admonished Mr. Trump for not directly responding to questions from Ms. James’s team.
“You can attack me. You can do whatever you want,” Justice Engoron told him, “but answer the question.”
When the judge turned to Mr. Trump with a simple request — “please no speeches” — his words drew a smirk from the former president, who continued to meander. At one point, Mr. Trump interrupted Kevin Wallace, a state lawyer questioning him, with an “Excuse me, sir,” so that he could opine about what he would have done had he in fact wanted to inflate the value of his assets.
“The net worth of me was far greater than the financial statements,” Mr. Trump scolded Mr. Wallace, later telling him that he should be “ashamed.”
“People like you go around and try to demean me and try to hurt me,” Mr. Trump told Mr. Wallace.
The testimony pushed Mr. Trump far outside his campaign-trail comfort zone to the controlled environs of a courtroom, where lying is a crime and outbursts can land you in contempt of court. The deeply personal nature of the trial for Mr. Trump, 77, whose obsession with his wealth is a defining feature of his celebrity, injected an extra dose of emotion into his testimony.
Mr. Trump is fighting Ms. James’s civil case while facing four criminal indictments implicating him in everything from a hush-money deal with a porn star to an attempt to undermine American democracy. While the cases are a distraction during his third White House run, Mr. Trump’s lead has only grown. He has cast himself as a political martyr under attack from Democrats like Ms. James and Justice Engoron.
Speaking with reporters after the testimony, Ms. James said that Mr. Trump had “rambled” and “hurled insults” but that “evidence demonstrated that in fact, he falsely inflated his assets to basically enrich himself and his family.”
Christopher M. Kise, a lawyer for Mr. Trump, thought otherwise: “In my 33 years, I have not had a witness testify better,” he said.
Even before Ms. James’s case went to trial, Justice Engoron had ruled that Mr. Trump’s financial statements were filled with fraud.
The trial will determine the punishment. Ms. James wants Mr. Trump to pay a $250 million penalty, be ousted from his company and be permanently barred from the world of New York real estate.
On Monday, as Mr. Wallace questioned Mr. Trump, the former president turned to the judge and lamented the way he had accepted Ms. James’s central contention before any evidence was heard in court: “You believed this political hack back there, and that’s unfortunate.”
“Done?” asked Mr. Wallace, like a parent asking a child if he was finished with a tantrum.
“Done,” responded Mr. Trump, and the questioning continued.
Throughout the roughly four hours of testimony, Mr. Trump alternately accepted and avoided responsibility. When Mr. Wallace asked how he ensured that the financial statements were handled properly, he passed the buck to financial lieutenants and outside auditors, saying, “I gave two people total authority to work with a very expensive accounting firm.”
Mr. Trump added, though, that he was not entirely hands-off: “I said, ‘Prepare the statements so that the accounting firm is happy.’”
Frequently, Mr. Wallace drew Mr. Trump in with simple questions about whether he had depended on the banks to rely on his financial statements. Mr. Trump affirmed that he had, without seeming to realize that the question went to intent, a necessary element for Ms. James’s lawyers to show.
He also couldn’t resist exaggerating in exactly the fashion that has left him vulnerable to the attorney general’s claims. When asked how big his triplex in Trump Tower is, he at first provided the accurate answer, 11,000 square feet. Seemingly unable to stop himself, he then said 12,000. Then, he said 13,000.
Mr. Trump also said that he had directed his employees to drop the value of his Westchester County, N.Y., estate, Seven Springs, because he “thought it was too high,” another acknowledgment of his involvement in the financial statements.
While that appeared to undercut Mr. Trump’s task on the stand — to distance himself from the valuation of his net worth — parts of his testimony may have helped him.
Mr. Trump gave a tutorial of sorts on real estate valuations, noting that a lower cash flow in a given year might not depress the overall value of his flagship office building in the Financial District. And he pointed out that the banks he is accused of defrauding actually made money, arguing that they were hardly victims.
He also spoke about moments of restraint.
When asked whether he approved the valuation for an office building, Mr. Trump said that he accepted it, not that he approved it, and did not instruct anyone to alter it. Asked if it was based on true and accurate information, the former president replied, “I hope so.”
Mr. Trump testified that he had an opinion on the worth of his properties, especially his Florida estate. “I thought that Mar-a-Lago was very underestimated, but I didn’t do anything about it,” he said. “I just left it be.”
But his expansive answers irritated the judge. As Mr. Trump spoke lovingly about Mar-a-Lago, calling it “beautiful” and a “success,” Justice Engoron looked up at the ceiling. The more Mr. Trump speechified, the more Justice Engoron rolled his eyes.
After Mr. Trump blurted that Aberdeen was the oil capital of Europe, Justice Engoron barked, “Irrelevant, irrelevant. Answer the question.”
In a criminal case, a jury or judge cannot hold a defendant’s refusal to answer questions against him. But this case is civil, and the rules are different: A judge can make what is called a “negative inference” — a damning assumption about why a defendant won’t answer.
At one point Monday, the judge, fed up with Mr. Trump’s nonresponsive responses, threatened to excuse the former president from the stand and assume the worst about why he wouldn’t answer.
Justice Engoron also repeatedly appealed to Mr. Trump’s lawyer, Mr. Kise, to rein in the former president. As Mr. Trump puckered his lips and shrugged his shoulders, Mr. Kise replied that Mr. Trump’s stature — as the “former and again soon-to-be chief executive of the United States” — afforded him leeway.
“Mr. Kise, can you control your client? This is not a political rally,” Judge Engoron said in the opening moments of the testimony, adding, “We’ll be here forever, and we’ll accomplish nothing.”
By the time Mr. Trump got up to leave the stand at the end of the day, the judge appeared relieved. He turned to the former president and held up his left hand in a goodbye wave.
Kate Christobek, Maggie Haberman, Nate Schweber, Liset Cruz, Claire Fahy and Susanne Craig contributed reporting.