Who is Donald Trump's former campaign manager Corey Lewandowski?

Mr Trump has repeatedly defended Mr Lewandowski

Corey Lewandowski - the brains behind Donald Trump's unlikely yet wildly successful presidential campaign - was perhaps as brash and unapologetic as his boss.

While Mr Trump's pugnacious style made him the front-runner, Mr Lewandowski's rough edges led to legal trouble for the campaign manager.

The 42-year-old's departure was announced on 20 June, with speculation it was to adapt the campaign to a run for the White House.

Mr Trump had previously told the Wall Street Journal he had "tremendous energy" and a "wonderful vision for politics".

Friction with the media

Mr Lewandowski had a fractious relationship with the press.

Earlier this year, he was charged with battery after allegedly yanking a female reporter, Michelle Fields, out of Mr Trump's way after a campaign event.

Mr Trump defended him throughout that incident, which concluded when the charges were dropped.

In new footage, the reporter (in cream jacket) is seen alongside Mr Trump before being held back

"They've really hurt a very good person... I don't discard people... I told him he should never settle this case," Mr Trump said at the time.

Mr Lewandowski tweeted shortly after the alleged assault that he had never met Ms Fields, much less touched her.

That was not the only physical altercation he was linked to - on 19 March, video appeared to show him grabbing a protester by his shirt collar during an Arizona rally.

There were also allegations that Mr Lewandowski had been sexually inappropriate in tone to female reporters during his work for Mr Trump and in a previous job, according to a lengthy report in Politico.

Office politics

However Mr Lewandowski, who is married with four children, was scarcely more popular with the rest of Trump's campaign team.

One Trump campaign director, Michael Caputo, tweeted "Ding dong the witch is dead" following the news he was leaving.

Lewandowski also did not get along with Trump chief strategist Paul Manafort either and blocked him from hiring staff, the New York Times reported.

And he is said to have had a fractious relationship with Trump's press secretary, Hope Hicks, and once rowed publicly with her on a New York street, according to US media.

Mr Lewandowski has denied assaulting Ms Fields

Politico's report said Trump campaign members at one point planned to deliver a letter to the presidential candidate's head of security, expressing concern about Mr Lewandowski's behaviour.

However, the plan was scrapped after Mr Trump won both the South Carolina and Nevada primaries.

Others complained about his alleged hot temper and use of profanity.

Taking a gun to work

The Massachusetts native and former lobbyist had also courted controversy in earlier jobs.

While working for Ohio Congressman Bob Ney in 1999, he was arrested after he brought a pistol into a congressional office building. He later said he brought the gun by mistake.

Mr Lewandowski also worked for the Republican National Committee, according to his LinkedIn page, and was later employed by Americans for Prosperity, a conservative advocacy group founded by billionaire conservative activist David Koch.