The resignation of Sean Spicer, the embattled White House press secretary, ends a tumultuous tenure attempting to defend President Donald Trump.
"It's been an honour and a privilege to serve @POTUS @realdonaldtrump & this amazing country," he tweeted.
Spicer's departure after six months and a day in the post was made public after the appointment of Anthony Scaramucci as White House communications director.
Spicer reportedly told friends he would resign if Scaramucci, a Wall Street trader and TV personality, was chosen for the top communications role. Scaramucci takes over from Mike Dubke, who resigned in May. Sarah Huckabee Sanders, Spicer's deputy, has become press secretary.
"This is obviously a difficult situation but I wish him well," said Scaramucci in the White House press room, repeatedly professing his "love" for Spicer and Trump. He praised the President and described chief of staff Reince Priebus, who reportedly opposed his appointment, as "like a brother".
Anthony Scaramucci, 52
The Harvard-educated millionaire is close to Trump's eldest son, Donald jnr, and respected by Ivanka and her husband, presidential adviser Jared Kushner.
A major Republican donor and founder of investment firm SkyBridge Capital, he served as an adviser on the presidential transition team.
Scaramucci is nicknamed "The Mooch" - except by former President George W. Bush, who reportedly calls him "Gucci Scaramucci".
The well-groomed banker previously hosted a financial television show, Wall Street Week, on Fox Business. In an August 2015 appearance on Fox Business Network, Scaramucci called Trump a "hack politician". Asked whether Trump was aware of the comment, Scaramucci joked to reporters the President mentions it every 15 seconds and called it one of his "biggest mistakes". He then looked to the cameras and said: "Mr President, if you're listening, I personally apologise for the 50th time for saying that."
Sean Spicer, 45
Spicer - awkwardly combative, cringingly defensive and ever-so-easy to parody - started out with a world-class disaster in an ill-fitting suit.
"This was the largest audience to ever witness an inauguration - period - both in person and around the globe," the former Republican National Committee official told reporters on January 21, just one day after Trump took the oath. The Washington Post's Fact Checker gave this claim its worst grade: Four Pinocchios.
Spicer became one of the most recognisable faces of Trump's administration, in part due to mockery by Melissa McCarthy, who parodied him to devastating effect on Saturday Night Live.
He was also criticised for appearing to downplay the Holocaust by saying that "even Hitler" had not stooped to the lows of Syria's Bashar al-Assad.
When FBI director James Comey was fired, Spicer was caught off guard and was described by the Washington Post as being forced to huddle with his team in bushes to develop an on-the-fly strategy.