Lady Manningham-Buller (born 1948) was educated at Northampton High School and Benenden School, and read English at Lady Margaret Hall, Oxford. She worked for three years as a teacher before joining the Security Service in 1974.
The main focus of her work was counter-terrorism, both international and domestic. She led the section responsible for international counter-terrorism at a time when its work was dominated by the Lockerbie investigation. She was later posted to Washington as a senior liaison officer to the US intelligence community. Her posting coincided with the first Gulf War. On her return to the UK in 1992, Eliza led a newly created Irish counter-terrorist section. This was formed in response to the Government's decision to make the Security Service in charge of intelligence work against Irish terrorism on the British mainland.
Eliza was promoted to the Security Service's Management Board in 1993. She served as the Director in charge of the Service's surveillance and technical operations. She was later appointed Director of Irish counter-terrorism. In 1997, she was appointed Deputy Director General. She had day-to-day responsibility for oversight of the Service's operational work and its liaison with other law enforcement and intelligence agencies.
Eliza was appointed Director General in October 2002 and retired in April 2007. She was appointed Dame Commander of the Order of the Bath (DCB) in HM The Queen's 2005 Birthday Honours. HM The Queen appointed her a Lady of the Garter in 2014.