The extramarital affair that ended David Petraeus‘s celebrated career last week raised many questions — and the case keeps taking new twists and turns. Among the key questions: when exactly the affair began, how the FBI stumbled upon the information and who was told about it. Here’s a timeline of events, according to officials involved in the investigation, as compiled by the Associated Press:

Spring 2006 — Paula Broadwell meets Petraeus at Harvard University, where she is a graduate student. Petraeus is a lieutenant general working on a manual about counterinsurgency and is invited to give a speech about his experiences in Iraq.