Former President Donald Trump's eldest son will be the first to take the stand in a civil fraud trial in New York that could severely restrict the family's business activities in the state.
Donald Trump Jr, Eric Trump, and their sister Ivanka Trump are all expected to testify.
Mr Trump's sons, who are senior Trump Organization executives and co-defendants in the case, are accused of falsification of business records, insurance fraud and conspiracy, among other claims.
Both deny any wrongdoing.
The $250m (£206m) fraud trial brought by New York Attorney General Letitia James accuses the former president of inflating the value of his properties.
Judge Arthur Engoron, who is overseeing the case, previously ruled that Mr Trump regularly lied on his financial statements and exaggerated his net worth by billions of dollars. The overvaluation allowed Mr Trump to obtain favourable loan rates and lower insurance premiums, the judge's ruling said.
The current case will decide penalties and whether the defendants broke any state laws in New York.
When are they due to testify?
Donald Trump Jr will take the stand on Wednesday, with Eric Trump expected to testify on Thursday, with a second day scheduled for questioning if needed.
Their father is scheduled to testify on Monday.
Lawyers for Ivanka Trump tried to quash a subpoena summoning her to testify in court. But the judge ruled she must appear, and she is set to be questioned next week, probably on Tuesday or Wednesday.
How are Don Jr and Eric Trump tied to the case?
Donald Trump Jr and Eric Trump have become political surrogates for their father, but they also kept the Trump Organization running while he was in the Oval Office.
Both are named defendants in the case and carry the title of executive vice-president in their father's company.
Those titles meant the two sons were "intimately involved in the operation of the Trump Organization's business", the New York Attorney General argued in court filings.
"They were aware of the true financial performance of the company", the prosecution added.
Eric Trump, who oversaw luxury golf developments for a time, denied he had anything to do with the valuation of Trump golf courses. He asserted that "I pour concrete, I operate properties, I don't focus on appraisals" in a video of his deposition.
While testifying earlier in the trial, David McArdle, a real estate executive who handled asset valuations for the Trump Organization, said Eric Trump's statement about not being involved was false, according to US media reports.
Donald Trump Jr, who had a key role overseeing commercial leasing, laughed off prosecutors' accounting questions, a video of his deposition shows.
Both brothers denied any knowledge of wrongdoing.
Why is Ivanka Trump being called to testify?
She was a defendant, but now Ivanka Trump is a witness in the case against her father and brothers.
The prosecution asserted in court filings that the eldest Trump daughter "was a primary point of contact and negotiator with Deutsche Bank" for three high-profile loans that are at the centre of the case. Ivanka Trump allegedly obtained one of the loans for the Old Post Office Building in Washington DC that stirred controversy for operating as the Trump International Hotel during her father's presidency.
They also contended that she remained "financially and professionally with the Trump Organization". The prosecution said she could be considered still under the "control" of the company and the defendants.
Ivanka Trump served as the executive vice-president for development and acquisition at the Trump Organization. She joined it in 2005, shortly after graduating from business school, and left to assist her father as an adviser in the White House in 2017.
She was previously a named defendant in the lawsuit, but an appeals court dismissed the case against her over the summer over statute of limitations issues.
Donald Trump's lawyers argued that Attorney General Letitia James was seeking "to harass and burden President Trump's daughter" by forcing her to testify.
Judge Engoron dismissed their argument and gave Ms Trump until Wednesday to appeal the decision.
Mr Trump reacted angrily to news his children would be taking the stand. He posted about it twice on social media and called the judge a "partisan political hack" and the case a "Witch Hunt".
Another co-defendant in the case is former Trump Organization Chief Financial Officer Allen Weisselberg, who has previously pleaded guilty to tax crimes.
Jeff McConney, a Trump Organization executive from 1987 until February 2023, was granted immunity in this case to flip against the Trumps, and testified that he helped company executives avoid taxes and inflated the former president's assets.
