Who is the former White House chief of staff replaced by Gen John Kelly following turf war with Anthony Scaramucci?

The US president's chief-of-staff is traditionally seen as the Oval Office "gatekeeper", a highly influential figure who oversees the actions of the White House staff, manages the president's schedule, and decides who is allowed to meet with him.  

But a Donald Trump administration was never going to shirk from shrugging off the constraints of tradition. 

From the very beginning, Reince Priebus, a veteran of Washington politics, had his work cut out managing a White House helmed by the unpredictable celebrity businessman and filled with a host of anti-establishment figures.

It was always a difficult task and it finally became impossible when Mr Trump defied Mr Priebus and brought in Anthony Scaramucci as his communications chief.

There was little love between the two men and the ill-feeling was laid bare on Twitter by Mr Scaramucci.

The White House was not big enough for the two of them, and it was Mr Priebus who was forced out.

Ever since his appointment, when Mr Trump stressed he would work as an equal alongside Washington revolutionary Steve Bannon, it was clear Mr Priebus would hold much less sway with the president than his predecessors enjoyed.  

Tensions have been building within Mr Trump's inner circle for months, but it was last week's appointment of communications director Anthony Scaramucci, hired over Mr Priebus' objections, that has left Mr Priebus in the tightest spot. 

It was already known that Mr Priebus had a tense relationship with Mr Scaramucci, who has made it clear that he reports directly to the president.

But a private feud erupted into open warfare on Wednesday when the communications chief suggested in a late-night tweet that Mr Priebus was one of the "leakers" that the president has railed against.

The New Yorker published an interview on Thursday in which Mr Scaramucci called the chief-of-staff a "paranoid schizophrenic".

Mr Scaramucci is the latest top aide to be granted a direct line to the president, and it has become increasingly unclear who actually reports to Mr Priebus.

Mr Priebus, 45, has more than a decade of experience in Republican politics and was seen as a safe pair of hands when he was given the role, the preferred choice of most senior Republicans. 

He was credited with smoothing over some of the rough edges of Mr Trump during the campaign, while charting a careful course between Mr Trump and the wary Republican establishment.

But the chief of staff has grown increasingly isolated in the White House, as past Republican National Committee colleagues and other allies have left or been pushed out of the West Wing. Those who have departed include former deputy chief of staff Katie Walsh, outgoing press secretary Sean Spicer and press aide Michael Short.

Mr Priebus has felt the brunt of Mr Trump's jokes at the expense of his staff and associates. At a meeting of auto company CEOs in Michigan in March, the president praised the executives and then said, "And then I look at Reince", drawing scattered laughs with a tone that suggested Mr Priebus was a less impressive presence. Mr Trump quickly added that his chief of staff had "done a great job."

Mr Priebus has been keeper of a gate that is permanently open. Top aides casually pop in constantly to speak with the boss.

"They've got all these chiefs running about with or without the title of chief," William Daley, the second chief of staff for President Barack Obama, told the Associated Press.

He said that under Mr Obama, there were high-ranking players with direct access to the president, but he was clued in on any policy or governing conversations, noting: "There was a sense that people were working together."

Ari Fleischer, who served as press secretary under George W. Bush, said there were multiple ways to effectively run the White House. George H.W. Bush ran a hierarchical West Wing with a powerful chief of staff who controlled access to the Oval Office. When his son came to office, he chose a different model, creating a system under which numerous senior aides were able to walk into the Oval Office and speak to the president, even if, on paper, they technically reported to someone else.

The difference now, he said, is that Mr Trump has created a faction-driven White House, noting: "I just think he has too many independent power centres and not enough team players."

House Majority Leader Paul Ryan threw his support behind his "close friend" on Tuesday", saying: "I think he's doing a great job as chief of staff."

But from within the White House, the silence was deafening. 

Asked on Fox whether Mr Priebus was in trouble, Ms Conway replied: "You'd have to ask the president that."