CIA boss David Petraeus forced to quit after FBI investigation found he was cheating on his loyal wife 'with married biographer'

Former general quits after 14 months as director of the CIA

Confessed to 'extremely poor judgement' in cheating on wife of 37 years

Affair 'was uncovered by FBI investigation on biographer, Paula Broadwell'

Broadwell is a married mother of two working on military PhD

First met Petraeus as he visited at Harvard, where she is a researcher



Obama pays tribute to Petraeus saying he made U.S. 'safer and stronger'

Deputy director Mike Morell takes over on temporary basis



CIA Director David Petraeus dramatically resigned today after allegedly having an affair with his biographer.



The alleged affair was uncovered after the FBI launched an investigation into the biographer, Paula Broadwell, for allegedly hacking into the former general's email, NBC News and Slate reported.



Broadwell, who researched the book 'All In' for three years, had extensive access to Petraeus in Afghanistan. Yet sources told NBC it is unlikely she will face criminal charges after the alleged hacking, stressing that Petraeus himself is under no investigation.



Petraeus stepped down today after confessing to cheating on his wife of 37 years, Holly - behaviour he explained was 'unacceptable' for a senior administration official.

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'Affair': Paula Broadwell and David Petraeus, pictured, reportedly had an affair that led to his resignation

He first met Broadwell six years ago when he addressed students at Harvard University, where she is a researcher, and they eventually got to know each other better during mile-long runs.

Broadwell, who served in the military for more than a decade, lives in Charlotte, North Carolina with her radiologist husband, Dr. Scott Broadwell, and their two young sons, Lucien and Landon.

In the biography, Broadwell revealed she first met him during his visit to Harvard in spring 2006 when he was a Commander at Fort Leavenworth.

'I was among the students invited by the school to meet with the general at a dinner afterward, because of my military background,' she explained.

'I introduced myself to then–Lieutenant General Petraeus and told him about my research interests; he gave me his card and offered to put me in touch with other researchers and service members working on the same issues.'



Broadwell added that this was not a one-off as he often 'does a lot of mentoring'.



'Other woman': Paula Broadwell, left, is married and has two children. Petraeus has been married to his wife Holly, pictured right, for 37 years, and they also have two children



Husband and wife: Paula Broadwell pictured with her husband and father of her children, Scott, a radiologist

As she pursued her PhD in public policy in 2008, she contacted him to ask if she could interview him and they kept in touch via email.



'A few months into my research, General Petraeus, who was then leading Central Command, invited me to go for a run with him and his team along the Potomac River during one of his visits to Washington,' she wrote. 'I figured I could interview him while we ran.'

She explained that, after earning varsity letters in cross-country and indoor and outdoor track, she wanted to test him to see if he could keep up with her as she interviewed him.



'Instead it became a test for me,' she said. 'As we talked during the run from the Pentagon to the Washington Monument and back, Petraeus progressively increased the pace until the talk turned to heavy breathing and we reached a six-minute-per-mile pace. It was a signature Petraeus move.'

Promoting the book on The Daily Show with John Stewart in January, she insisted that these mile-long runs together were nothing out of the ordinary.



'This is a typical mechanism for him to get to know young people,' she said. 'He's done it throughout his life. That was the foundation of our relationship.'

VIDEO: ANALYSIS - CIA boss David Petraeus forced to quit after cheating on his wife





Close: Broadwell first met Petraeus when he visited Harvard University, where she was a student

Embedded: Broadwell, pictured in Afghanistan, has more than a decade of U.S. military service

Devoted: Broadwell, pictured with Lt Col. Steve Grenier in Gizab, also writes opinion pieces on leadership

In another often awkward radio interview in January, host Don Imus said that the pair must have 'obviously' liked each other.

She responded: 'You know, as I said earlier, he has a number of mentees and that's one thing that's different when you compare him to other Senior Commanders.

Author: Broadwell completed a biography about Petraeus, published earlier this year

'But, yeah, we had a lot of rapport. I think some of that comes from a common ground of having gone to West Point [to the U.S. Military Academy].'

Of her reported rival, she added: 'He is married to Holly Petraeus, who is a wonderful Military spouse and done so much for their children and for children of fallen soldiers, I respect her immensely.'

The book's description explains Broadwell conducted research for three years and was 'afforded extensive access by General Petraeus, his mentors, his subordinates and his longtime friends'. Its website adds Broadwell was embedded in Afghanistan with Petraeus for a year between July 2010 and 2011.



Broadwell graduated with honors from the U.S. Military Academy in West Point, and came top of her class in physical fitness. Petraeus also attended the academy and married his wife Holly there.

She has more than a decade of military service and nearly two decades of work in counterterrorism and counterinsurgency.

She is studying for her PhD at Kings College in London, and is also a research associate at Harvard University's Center for Public Leadership. For her studies and the biography, she spent most of 2011 in Afghanistan as an embedded author.

As well as contributing to book chapters, appearing on television interviews and writing opinion pieces for The New York Times and the Boston Globe about leadership and women in defense, she has also worked as a model and demonstrator for KRISS, a .45 caliber machine gun manufacturer.

Last week, Broadwell wrote an article entitled 'David Petraeus's Rules for Living' in Newsweek.

Ally: Barack Obama could be harmed by the loss of one of his senior national security officials

One read: 'We all will make mistakes. The key is to recognize them and admit them, to learn from them, and to take off the rear view mirrors - drive on and avoid making them again.'