BBC NEWS | World | Americas | Bush under pressure in leak row:

6 Jul 2003: Joseph Wilson questions US claims about Iraq nuclear programme
8 Jul: Libby leaks classified information to reporter Judith Miller, but not agent's name, he later testifies
14 Jul: Columnist Robert Novak identifies Wilson's wife as CIA agent
30 Sept: Justice dept launches inquiry into agent's outing
28 Oct 2005: Libby charged with obstruction and perjury
6 Apr 2006: Court papers suggest Bush authorised leak of classified material (not agent's identity)