_February 2002: Former Ambassador Joseph Wilson is asked by the Bush administration to travel to Niger to check out an intelligence report that Niger sold yellowcake uranium to Iraq in the late 1990s for use in nuclear weapons.
_Jan. 28, 2003: In his State of the Union address, President George W. Bush states that "The British government has learned that Saddam Hussein recently sought significant quantities of uranium from Africa" but does not mention that US agencies had questioned the validity of the British intelligence.
_July 6: In a New York Times op-ed piece, Wilson writes that he could not verify that Niger sold uranium yellowcake to Iraq.
_July 14: Columnist Robert Novak identifies Wilson's wife, Valerie Plame, as "a (CIA) operative on weapons of mass destruction." Novak cites "two senior administration officials" as his sources.
_July 17: Matthew Cooper writes on Time.com that government officials have told him Wilson's wife is a CIA official monitoring WMD. Another article appears in the magazine's July 21 print issue.
_Sept 29-30: The Justice Department informs then-White House counsel Alberto R. Gonzales that it has opened an investigation into possible unauthorized disclosures concerning the identity of an undercover CIA employee. Gonzales informs the president the next day. Bush tells reporters: "I don't know of anybody in my administration who leaked classified information. If somebody did leak classified information, I'd like to know it, and we'll take the appropriate action."
_Dec. 30: US Attorney Patrick J. Fitzgerald is named special counsel to investigate whether a crime was committed.
_May 21, 2004: A grand jury subpoenas Cooper and Time Inc., seeking testimony and documents. Time says it will fight subpoena.
_Aug 9: US District Judge Thomas F. Hogan rejects claims that the US Constitution's provision for freedom of the press protects Cooper from testifying and finds Cooper and Time in contempt of court. Time magazine appeals the ruling.
_Aug 12 and 14: The grand jury subpoenas New York Times reporter Judith Miller, who gathered material for a story but did not write one. The New York Times says it will fight subpoena.
_Aug 24: Cooper agrees to give a deposition after I. Lewis "Scooter" Libby, Vice President Dick Cheney's chief of staff, personally releases Cooper from a promise of confidentiality.
_Sept 13: According to court documents, the grand jury issues a further subpoena to Cooper seeking additional information relating to the case. Cooper and Time move to quash the subpoena.
_Oct 7: Hogan holds Miller in contempt.
_Oct. 13: Cooper and Time held in contempt.
_Feb. 15, 2005: Appeals court rules against Miller and Cooper. Both Time magazine and The New York Times appeal to the Supreme Court.
_June 27: The Supreme Court refuses to intervene.
_July 1: Time magazine agrees to comply with a court order to turn over Cooper's notes, e-mail and other documents. Cooper and Miller continue to refuse to divulge sources.
_July 6: Hogan sends Miller to jail for refusing to divulge her source.
_July 7: Bush tells reporters that if anyone in his administration committed a crime in connection with the leak, that person "will no longer work in my administration."
_July 15: Presidential aide Karl Rove testifies to the grand jury that he learned the identity of the CIA operative originally from journalists, then informally discussed the information, without using Plame's name, with Cooper.
_Sept. 29: After 85 days behind bars, Miller is released from the city jail in Alexandria, Virginia, after agreeing to testify before a grand jury. She says her source has "voluntarily and personally released me from my promise of confidentiality."
_Sept. 30: Miller testifies at the federal courthouse in downtown Washington, ending her silence in the investigation.
_Oct. 6: Rove agrees to testify again before the grand jury. Prosecutors say they cannot guarantee he will not be indicted.
_Oct. 11: Miller testifies again and turns over notes of a previously undisclosed phone conversation with Libby.
_Oct. 12: Miller completes her grand jury testimony.
_Oct. 13: Hogan lifts contempt order against Miller.
_Oct. 14: Rove testifies again.
_Oct. 16: Miller writes about her testimony in a New York Times article, saying she can't recall who told her Plame's name. She says Libby told her that Wilson's wife worked for the CIA's Weapons Intelligence, Non-Proliferation, and Arms Control (WINPAC) unit.
_ Oct. 17: In a press conference, Bush declines to say whether he would remove an aide under indictment.
_ Oct. 19: The Associated Press reports that Rove told grand jurors it was possible he first learned from Libby that Plame worked for the CIA.
_ Oct. 21: Reports surface that Miller belatedly gave prosecutors her notes of a meeting with Libby only after being shown White House records showing that the two had met as early as June 23, 2003.
_ Oct. 25: The New York Times reports that notes suggest that Cheney passed on Plame's identity to Libby in a previously undisclosed June 12, 2003, conversation.
_ Oct. 26: Fitzgerald meets with grand jury as panel winds up two-year investigation.
_ Oct. 28: Libby is charged with perjury and other counts in the CIA leak investigation; he resigns and leaves the White House. No charges are filed against Karl Rove, but he remains under investigation. The grand jury's term expires.