Donald Trump testifies: What to expect when former president takes the stand

Former President Donald Trump is scheduled to testify in the civil fraud trial that threatens his family's business empire.

His testimony on Monday will follow those of two of his sons - Donald Trump Jr and Eric Trump - who took the stand late last week.

New York's attorney general is seeking a $250m (£202m) fine and a ban on Mr Trump doing business in the state.

The judge has already ruled that the former president, along with his two oldest sons and other Trump Organization executives, committed fraud. These proceedings will determine potential penalties.

Mr Trump, 77, denies wrongdoing.

It is unprecedented for a former president to take the witness stand, presidential historian Lindsay Chervinsky told the BBC.

Here is what to expect from Mr Trump's highly anticipated testimony:

No one is quite sure what the former president will do. He has called the proceedings a political witch hunt.

Dr Chervinsky said Mr Trump's testimony goes against every political communications strategy in history.

"A president's speech is supposed to be fairly carefully curated," she said. "In a trial, you never know what's going to come up."

The frontrunner for next year's Republican presidential nomination has not testified publicly in any of the other ongoing legal cases against him.

But he has already clashed with the judge overseeing the case, Arthur Engoron, who twice ruled that Mr Trump had violated a gag order forbidding him from criticising court staff and fined him $15,000, total.

In Monday's turn on the witness stand, he is to face a grilling, under oath, about evidence the trial has heard that he directed asset values to be fraudulently inflated so his company could secure favourable loans.​

And it's clear that Mr Trump is following this case - one that could see him stripped of some corporate holdings and signature properties such as Trump Tower - closely.

The former president has frequently attended the trial in person and shared his displeasure about his former lawyer Michael Cohen, the judge, the attorney general, and even court employees throughout the trial.

When Mr Cohen testified against him, Mr Trump abruptly left court after the judge ruled against him. Apparently caught off-guard, his Secret Service detail hurried to catch up with him.

Mr Trump is no stranger to court cases. He has been involved in a number of legal disputes over the years, ones that have at times led to him taking the stand or giving depositions.

He has previously invoked his constitutional right against self-incrimination, known as pleading the fifth, in this case.

While testifying under oath in a deposition, which is out-of-court oral testimony, Mr Trump pleaded the fifth more than 400 times.

That does not mean he will do the same on the witness stand.

Eric Trump invoked that particular constitutional right more than 500 times while testifying under oath in a deposition,

But that did not stop him from sparring with state's attorneys when he took the witness stand in court.

There have been several remarkable moments in the Trumps' court case thus far.

His sons' turns on the stand were particularly memorable. Both maintained their innocence.

Donald Trump Jr cracked jokes.

"I should have worn make-up," he said to photographers and asked a court sketch artist to make him "look sexy".

There are others testifying in the case as well.

Another co-defendant 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 this year, was granted immunity in this case to flip against the Trumps. He testified that he had helped company executives avoid taxes and inflated the former president's assets.