At an Institute of Politics Forum in 2006, General David H. Petraeus met Paula D. Broadwell for the first time. This encounter would later develop into the relationship that caused him to resign as Central Intelligence Agency Director on Friday.

Petraeus admitted to having an extramarital affair in a statement after submitting a letter of resignation to President Barack Obama.

Broadwell, who cowrote a biography of Petraeus entitled “All In: The Education of General David Petraeus,” became close to Petraeus while he led coalition forces as a four-star general in Afghanistan. Petraeus previously led coalition forces in Iraq and oversaw military operations throughout the Middle East as Commander of United States Central Command.

Broadwell mentions Petreaus’s 2006 visit to Harvard in the first sentence of the biography and recalls attending a dinner with the General and other students.

Broadwell, who, like Petraeus, attended the United States Military Academy at West Point, writes that Petreaus gave her his card, and she followed up with an email.

“I later discovered that he was famous for this type of mentoring and networking, especially with aspiring soldier-scholars,” Broadwell writes in the biography. “He immediately responded to the e-mail, inviting me to bounce ideas off him. I took full advantage of his open-door policy to seek insight and share perspectives.”

Broadwell’s work on the book followed her 2008 graduation from the Kennedy School with a Masters in Public Administration. Currently, she is listed as a research affiliate of the Kennedy School’s Center for Public Leadership and a PhD candidate in the Department of War Studies at King’s College in London.

Broadwell spoke about her book at an Institute of Politics event in September.

Broadwell did not respond to a request for comment, and her website, paulabroadwell.com, was taken offline Friday.

In a letter to colleagues at the CIA on Friday, Petraeus cited “personal reasons” for his resignation and said that he had used “extremely poor judgement” after being married for 37 years.

“Such behavior is unacceptable, both as a husband and as the leader of an organization such as ours,” Petraeus wrote.

Obama, along with other national leaders, reflected on the career of someone that they described as an important military leader and public servant.

“By any measure, through his lifetime of service David Petraeus has made our country safer and stronger,” Obama said in a statement. “Going forward, my thoughts and prayers are with Dave and Holly Petraeus.”

According to both NBC News and Politico, Broadwell is now under investigation by the Federal Bureau of Investigation for trying to access Petraeus’s personal emails.

—Staff writer Samuel Y. Weinstock can be reached at sweinstock@college.harvard.edu.