Donald Trump will set foot in a New York courthouse on Monday and become the first former US president to stand trial in a criminal case.
He is accused of falsifying his business records to disguise a hush-money payment made to Stormy Daniels, a former adult film star, shortly before the 2016 election.
Trump, 77, faces a maximum of four years in jail if convicted, but could avoid jail time and be fined instead.
He has pleaded not guilty.
Trump's historic trial will take place against the backdrop of his presidential campaign, and could ultimately see the presumptive Republican nominee become a convicted felon months before voters head to the polls in November.
"It's unprecedented," said Alex Keyssar, a professor of history and public policy at Harvard University's Kennedy School. "There's been nothing remotely comparable to it."
The trial, which will begin with jury selection on Monday, is expected to last six to eight weeks and will centre around a reimbursement Trump made to his former fixer Michael Cohen.
Cohen, 57, claims he was directed to pay Ms Daniels $130,000 (£104,000) in exchange for her silence about an alleged affair with Trump, something prosecutors have described as an attempt to "unlawfully influence" the 2016 election.
Hush money payments are not illegal. But the Manhattan District Attorney's Office alleges that Trump committed a crime by improperly recording the reimbursement to Cohen as legal expenses.
In total, he is accused of 34 felony counts of falsifying business records in the first degree. To reach a verdict, all 12 jurors must agree on whether Trump is guilty or not guilty of a specific charge.
"It's unprecedented," said Alex Keyssar, a professor of history and public policy at Harvard University's Kennedy School. "There's been nothing remotely comparable to it."
The trial, which will begin with jury selection on Monday, is expected to last six to eight weeks and will centre around a reimbursement Trump made to his former fixer Michael Cohen.
Cohen, 57, claims he was directed to pay Ms Daniels $130,000 (£104,000) in exchange for her silence about an alleged affair with Trump, something prosecutors have described as an attempt to "unlawfully influence" the 2016 election.
Hush money payments are not illegal. But the Manhattan District Attorney's Office alleges that Trump committed a crime by improperly recording the reimbursement to Cohen as legal expenses.
In total, he is accused of 34 felony counts of falsifying business records in the first degree. To reach a verdict, all 12 jurors must agree on whether Trump is guilty or not guilty of a specific charge.
Trump has made several unsuccessful attempts to delay the jury trial and move it from Manhattan, which is comprised predominantly of Democrats.
His fiery remarks about the case, which he has repeatedly described as politically motivated, led the judge to impose a gag order which bans him from making public comments about people related to the case, including witnesses.
The order was extended after Trump turned his online attacks to the judge's daughter, calling her a "Rabid Trump Hater".
The Trump campaign said the gag order was unconstitutional and violated his free speech rights.
This criminal case is just one of four Donald Trump is facing this year. But it could be the only trial to take place before his 2024 election rematch with President Joe Biden.
As a first-time offender, even if Trump is convicted, experts say he is unlikely to go to prison. Even if he did, under US law, he could still serve as president.
But his conviction would mark the first time a felon has run for president as a major-party nominee, Keyssar said.
"What's remarkable about this is that it doesn't seem to bother a significant portion of the electorate," Keyssar said, noting Trump's popularity has not suffered as a result of his criminal indictments.
But the potential court drama will place him at the centre of the news cycle with just months to go before the election.
And that heightened attention means that any small news from court - good or bad for Trump - could play a role in the race between the former and current president, said Georgetown University government Professor Hans Noel.
"I expect this to be a very close election," he said, "and so any small thing could matter".
