Elizabeth Lydia "Eliza" Manningham-Buller, Baroness Manningham-Buller, DCB (born 14 July 1948) was Director General of MI5, the British internal Security Service (MI5), from October 2002 until her retirement on 20 April 2007, aged 58. She became a crossbench life peer on 18 April 2008. Her title was gazetted as Baroness Manningham-Buller, of Northampton in the County of Northamptonshire on 2 June 2008.