Gen. David Petraeus pleaded guilty Tuesday to one federal charge of removing and retaining classified information as part of a plea deal, court documents show. According to the documents, Petraeus admitted removing several so-called black books – notebooks in which he kept classified and non-classified information from his tenure as the commander of the International Security Assistance Force in Afghanistan – and giving them to his biographer, Paula Broadwell. On November 9, 2012, he resigned from his CIA post, citing personal reasons. Petraeus allegedly provided classified intelligence to his lover, Broadwell, while he was director of the CIA. The married mother of two and former military officer was writing a book about the general at the time. During his time as commander in Afghanistan, Petraeus kept personal notes including classified information in eight 5-by-8 inch black notebooks. The classified information including identity of covert officers, war strategy, notes from diplomatic and national security meetings and security code words. David Petraeus fast facts In August 2011, according to the court documents, Petraeus dropped off the notebooks to a house in Washington, D.C., so Broadwell could access them. He later retrieved them and brought them to his home in Arlington, Va. After Petraeus resigned in 2012 he told the government he had no classified materials in his possession. That turned out not to be true when the FBI in April 2013 conducted a search of his house and found the black notebooks in an unlocked desk drawer in a first floor study. When he was questioned by the FBI, he lied and claimed that he had never provided classified information to anyone not authorized to have it, according to the court documents. The relationship came to light during an FBI investigation into a complaint that Broadwell was allegedly sending harassing e-mails to another woman who was close to Petraeus, a U.S. official told CNN in January. Petraeus now works for New York private equity firm KKR & Co. Lawyers for Petraeus declined to comment.