Former FBI deputy director William Mark Felt, Sr., age 91, broke his 30-year silence and confirmed in June 2005 that he was “Deep Throat,” the anonymous government source who had leaked crucial information to Washington Post reporters Carl Bernstein and Bob Woodward, which helped take down President Richard M. Nixon during the Watergate scandal.

Watergate began in June 1972 when five robbers linked to Nixon’s re-election campaign were caught red-handed wiretapping phones and stealing documents inside the Democratic National Committee’s office in Washington, D.C.’s Watergate office complex.

Nixon – who denied involvement or knowledge of the incident – then participated in an extensive cover-up.

Throughout the 1972 election campaign and beyond, Deep Throat fed Woodward and Bernstein a steady flow of information which exposed Nixon’s knowledge of the scandal.

The idea to break into the Democratic National Committee’s office and tap their phones was the brainchild of G. Gordon Liddy, Finance Counsel for the Committee for the Reelection of the President (CRP). He took his plan to White House Counsel John Dean and Attorney General John Mitchell, who approved a smaller-scale version of the idea.

The initial break-in and wiretapping went without a hitch; however, when the burglars returned to the scene of the crime to fix some broken wiretaps on June 17, 1972, they were caught red-handed and arrested.

After the arrests, Liddy and his accomplices scrambled to destroy evidence as the Nixon propaganda machine went into full gear. They vehemently denied they, the President or anyone in the White House were involved with the break-in, even though a $25,000 check allotted for Nixon’s campaign mysteriously ended up in the bank account of a real estate firm owned by one of the robbers.

At the time of the break-in, Felt was second-in-command at the FBI and in charge of day-to-day operations. He was essentially point man for the FBI investigation into the crime.

Felt and his staff interviewed dozens of CRP members, but the meetings were also attended by White House lawyers. Felt believed transcripts of the interviews were passed on to White House counsel John Dean by acting FBI director Patrick Gray.

Felt knew Nixon was involved in Watergate but after a few months of the investigation being derailed by an uncooperative White House, it seemed his connection would remain a well-guarded secret. Knowing there was much more to the story, Felt took matters into his own hands and began leaking information to Woodward.

Bob Woodward and Carl Bernstein, then both in their 20s, rode the Watergate investigation hard right out of the gate.

According to their books, All the President’s Men and The Secret Man: The Story of Watergate’s Deep Throat, Woodward spoke with Felt 17 times between June 1972 and November 1973, sometimes by phone but also in person at a parking garage in Rosslyn, Virginia, and often using clandestine tactics to keep from being discovered.

Felt never let Woodward or Bernstein quote him directly and at first only confirmed existing leads. As the investigation unfolded, however, he offered some new information.

The moniker “Deep Throat” referred to a controversial but widely viewed pornographic film of the same name that was released in 1972.

In October of that year, Watergate was finally linked to Nixon when the FBI determined the operation was a massive setup of spying and sabotage by Nixon’s aides to support his re-election.

Woodward and Bernstein kept the pressure on as Nixon’s White House fought back and claimed their ambitious reporting was nothing more than “a witch hunt.”

The White House’s tactics seemed to work, though, and Nixon was re-elected by a landslide in November. Still, much to Nixon’s dismay, the Watergate investigation—with Woodward, Bernstein and Deep Throat at the helm—only escalated.

As the Watergate burglars and their collaborators were convicted, it was clear Nixon knew much more than he had let on. White House Counsel John Dean and other Nixon aides eventually testified that Nixon had abused his power by ordering the CIA to hinder the FBI’s investigation into the scandal.

It was also revealed that Nixon had recorded every conversation in the Oval Office during his presidency and that the tapes of those conversations would contain proof he had obstructed justice.

A bitter, months-long legal battle over the tapes then ensued between Nixon’s lawyers and Special Prosecutor Archibald Cox. Nixon ordered Cox fired but eventually surrendered some of the tapes. In July 1974, a Supreme Court order forced him to turn over the remaining recordings.

Knowing they would directly tie him to Watergate—and with impeachment imminent—Nixon resigned the presidency on August 8, 1974. In all, 40 people were convicted on felony charges for crimes linked to Watergate.

Woodward and Bernstein published All the President’s Men two months before Nixon resigned. The book spurred varying opinions about the identity of Deep Throat.

The White House suspected Felt and as the investigation dragged on, Felt lived in dread of being discovered and losing his job – or worse. But Woodward went all out to protect his source and would continue to safeguard the truth long after the Watergate scandal had ended.

In February 1973, Nixon appointed Gray permanent FBI director. His tenure was short, however, when he was forced to resign after it came to light he had destroyed a file on CIA Officer E. Howard Hunt, one of Liddy’s Watergate co-conspirators. Gray then recommended Felt for the job, but Nixon and his Chief of Staff Alexander Haig were concerned Felt was leaking information to the press and chose William Ruckelshaus instead.

Felt and Ruckelshaus had a strained relationship. In June, Ruckelshaus directly accused Felt of leaking information to The New York Times. On June 22, Felt resigned and ended his 31-year career with the FBI.

In 1978, Felt was indicted for ordering FBI agents to search the homes of Weather Underground members and other leftist groups without a warrant. He was found guilty in 1980 and pardoned by President Ronald Reagan in 1981.

During that time, Felt wrote his memoir and claimed he was not Deep Throat. His wife died in 1984 and he eventually moved to California (where he survived a stroke in 1999).

For 30 years, Felt, Woodward and Bernstein kept Deep Throat’s identity a secret. Even when the story of Watergate was made into the blockbuster movie All the President’s Men starring Robert Redford, Dustin Hoffman and Hal Holbrook, Felt and company stayed mum.

Felt reportedly even denied the truth to his family, friends and closest colleagues. That is, until May 2005 when an ailing Felt announced in a Vanity Fair article, “I’m the guy they used to call Deep Throat.”

Reportedly, Felt’s family had figured out his pseudo-identity and encouraged him to tell the world. Felt struggled with the decision, however, and was concerned about how it would affect the family and his legacy. It wasn’t until his family suggested the truth might help them pay some bills that he agreed to share his story.

The reaction to the Vanity Fair article was mixed. Some people considered Felt an American hero for fighting for justice; others thought him a disloyal traitor. Once Felt came forward, Woodward and Bernstein confirmed he was Deep Throat.

The pair also cautioned people to remember that Deep Throat was just one factor of a mammoth investigation which included other sources, Senate hearings and the infamous Nixon Oval Office recordings, among other things.

“Felt’s role in all this can be overstated,” said Bernstein in an interview after Felt broke his silence. “When we wrote the book, we didn’t think his role would achieve such mythical dimensions. You see there that Felt/Deep Throat largely confirmed information we had already gotten from other sources.”

On December 18, 2008, Felt died of heart failure at the age of 95. Whether he was a courageous patriot willing to risk everything for justice or a turncoat hoping to take down a sitting president is up to individuals and history to decide.

What’s certain is Deep Throat played a critical role in ending the Nixon administration, and Woodward and Bernstein’s reporting brought new meaning to the term “investigative journalism,” inspiring a generation of investigative reporters.