By Matthew Davis BBC News, Washington

Watergate is the most notorious political scandal in American history, and Deep Throat the most famous unidentified single source in journalism.

Deep Throat's leaks led to the resignation of Richard Nixon

What began as a seemingly innocuous burglary in June 1972 led to the downfall of President Richard Nixon.

It also unearthed a web of political spying, sabotage and bribery.

Some say it changed American political culture forever, knocking the president from his pedestal and emboldening the media.

Washington Post reporters Bob Woodward and Carl Bernstein played a key role in bringing the scandal to light, aided by crucial information from their mysterious informant.

Political nightmare

Watergate is a general term used to describe a complex web of political scandals between 1972 and 1974.

WATERGATE IN DATES 17 June 1972: Burglary at Watergate complex 11 Nov 1972: Nixon re-elected 30 Jan 1973: Seven convicted for Watergate break-in 18 May 1973: Senate begins televised hearings into scandal 17 Nov 1973: Nixon declares 'I am not a crook' 27 July 1974: House impeaches Nixon 8 August 1974: President Nixon resigns

But it also refers specifically to the Watergate complex in Washington DC which houses a hotel and many business offices.

It was here on 17 June 1972 that five men were arrested trying to bug the offices of the Democratic National Committee.

The break-in, during that year's election campaign, was traced to members of a Nixon-support group, the Committee to Re-elect the President.

The burglars and two accomplices were convicted in January 1973, with many, including trial judge John Sirica, suspecting a conspiracy reaching the higher echelons of power.

The affair transformed into a wider political scandal when one of the convicted burglars - who like the others had received a heavy sentence for his silence over the affair - wrote to Sirica alleging a massive cover-up.

Secret recordings

The Senate launched investigations that engulfed major political players including former attorney general John Mitchell and chief White House advisers John Ehrlichman and HR Haldeman.

Bernstein and Woodward broke many stories as the scandal grew

In April 1974, Nixon bowed to public pressure and released edited transcripts of his taped conversations relating to Watergate.

But it failed to stop the steady erosion of support for his administration, or a public perception that he was implicated in the conspiracy.

In July that year, the Supreme Court ordered Nixon to turn over the tapes relating to the scandal.

Meanwhile, the House of Representatives' Judiciary Committee completed its investigation and passed three articles of impeachment against Nixon.

On 5 August, Nixon gave up transcripts of three recorded conversations.

He admitted he had been aware of the cover-up shortly after the Watergate break-in and that he had tried to halt the FBI's inquiry.

Four days later, he became the only US President to resign from office and was replaced by Vice-President Gerald Ford.

President Ford pardoned Nixon to avoid a trial, while Nixon's chief associates, Haldeman, Ehrlichman and Mitchell, were among those convicted in 1975 for their role.

'Follow the money'

Woodward and Bernstein broke many of the stories as the scandal grew. Their book on the scandal, All the President's Men, became a movie starring Dustin Hoffman and Robert Redford.

Mark Felt says he was Deep Throat

Memorable scenes include Woodward's first meeting with Deep Throat, who lights a cigarette in a dark, dismal parking garage, and the source exhorting Woodward to "follow the money".

As Watergate unfolded, Deep Throat became nervous that his role in the Post's investigation would be discovered, Woodward has said.

He is believed to have demanded that the two stop conversing by phone, thinking that the line may be tapped, and they began meeting late at night in a Washington parking garage.

If Woodward wanted a meeting with Deep Throat, the reporter would rearrange a potted plant in his apartment window.

If Deep Throat wanted a meeting with Woodward, he would somehow ensure that page 20 of Woodward's daily New York Times delivery was circled.

For decades there has been speculation about who Deep Throat was, with the cloak-and-dagger intrigue only fuelling the mystery.

Now, the speculation has finally come to an end.