US President Donald Trump's defence team in his Senate trial will include special prosecutors from President Bill Clinton's impeachment.
He will be represented by Ken Starr and Robert Ray, who investigated Mr Clinton, and Alan Dershowitz, whose past clients include OJ Simpson.
White House counsel Pat Cipollone and Mr Trump's personal lawyer Jay Sekulow will lead the team.
Opening statements in the Trump impeachment trial will begin next week.
Who are the Clinton prosecutors?
Mr Starr was the US Department of Justice independent counsel who investigated the Whitewater affair, a scandal-plagued mid-1980s land venture in Arkansas involving Bill and Hillary Clinton.
The inquiry ultimately uncovered unrelated evidence that Mr Clinton had been having an affair with a White House intern, Monica Lewinsky.
The investigation culminated in the Democratic president's impeachment by the US House of Representatives in 1998. Mr Clinton was acquitted by the Senate.
Mr Ray succeeded Mr Starr as the independent counsel.
Ms Lewinsky tweeted on Friday shortly after Mr Trump's team was announced: "This is definitely an 'are you kidding me?' kinda day", though she inserted an expletive.
In 2016, Mr Starr was forced out of his position as president of Baylor University after an inquiry found the school had mishandled rape accusations against its football players.
He later also resigned from his roles as chancellor and law professor at the university.
Who is Alan Dershowitz?
Mr Dershowitz is a retired Harvard University law professor and constitutional law expert whose past celebrity clients have also included boxer Mike Tyson.
He told CBS News, the BBC's US partner, that he had spoken to the president on Wednesday about the impeachment case.
"I agreed to do it as an independent constitutional scholar," Mr Dershowitz said. "I take no position on the politics - just on the constitution."
He added he was "very, very concerned" about the precedent this impeachment could establish.
"It could weaken the presidency and weaponise impeachment as a partisan tactic," he said.
Mr Dershowitz said in a statement that he had also opposed Mr Clinton's impeachment, and voted for Hillary Clinton in the 2016 election.
The president sought Mr Dershowitz's advice, too, during the 2017-19 special counsel investigation into alleged Russian meddling in the US presidential election.
Mr Dershowitz and Mr Starr both represented disgraced financier Jeffrey Epstein during his 2008 abuse trial.
Axios reported that some White House officials were against Mr Dershowitz joining the team, given his ties to Mr Epstein.
On Friday, the president shared Mr Dershowitz's comments criticising a Government Accountability Office ruling that the White House had broken the law by withholding aid to Ukraine.
“The GOA got it exactly backwards. Here’s what they said. The law does not permit the President to substitute his own policy priorities to those Congress has enacted into law. It’s exactly the opposite. The Constitution does not allow Congress to substitute its own priorities....— Donald J. Trump (@realDonaldTrump) January 17, 2020
Who else is on the legal team?
Former Florida Attorney General Pam Bondi has also been asked to join the team.
Mrs Bondi, a longtime Trump ally, joined the White House communications team last November to focus on "proactive impeachment messaging".
The president's personal attorney Rudy Giuliani, a central figure in the Ukraine investigation, had also hoped to join the defence, but he did not make the cut.
Mr Giuliani told CBS he might be called as a witness in the impeachment trial and "understood this may happen if I uncovered the 2016 Ukrainian corruption".
He was apparently referring to a discredited theory that Ukraine intervened in the last White House election.
One of Mr Giuliani's associates, Ukrainian-American businessman Lev Parnas, has said he went to Ukraine to pressure local officials on behalf of Mr Trump and Mr Giuliani.
Mr Trump's allies have rubbished Mr Parnas' claims, pointing out that he is facing unrelated campaign finance charges.
Why was Trump impeached?
Mr Trump was impeached by the US House of Representatives last month on charges of abuse of power and obstruction of Congress.
Democrats have accused him of withholding military aid to Ukraine to pressure the country into investigating his political rival, former US Vice-President Joe Biden.
Mr Trump denies the claims, and calls the impeachment proceedings a partisan "hoax".
The Republican president now faces a trial in the Senate, which must decide whether to remove him from office.
As his Republican party holds a majority in the upper chamber, he is expected to be acquitted.
Want to find out more on impeachment?
- A SIMPLE GUIDE: If you want a basic take, this one's for you
- GO DEEPER: Here's a 100, 300 and 800-word summary of the story
- A STATE DIVIDED: What New Hampshire makes of it
- YOUR QUESTIONS: Will Trump really testify?
- HISTORY: Can an impeached president remain popular?
- CASE FOR & AGAINST: What legal scholars say about Trump conduct
- WHAT'S IMPEACHMENT? A political process to remove a president