Petraeus previously served as a four-star general who was a member of the U.S. Army for over 37 years.
His last assignments in the Army include commander of the International Security Assistance Force (ISAF) and Commander, U.S. Forces Afghanistan (USFOR-A) from July 4, 2010 to July 18, 2011.
Petraus also served as the 10th Commander, U.S. Central Command (USCENTCOM) from October 13, 2008, to June 30, 2010, and as Commanding General, Multi-National Force - Iraq (MNF-I) from February 10, 2007, to September 16, 2008.
As commander of MNF-I, Petraeus was responsible for the coordination of all coalition forces in Iraq.
According to reports
, Petraeus asked President Barack Obama on Thursday to allow him to resign, and on Friday the president accepted.
Petraeus said in a statement that he had shown "extremely poor judgment" in having an affair, however details of the affair and the woman involved were not available at press time.