Stella Rimington joined the Security Service (MI5) in 1965 and during her career she worked in all the main fields of the Service's responsibilities - counter-subversion, counter-espionage and counter-terrorism - and became successively Director of all three branches. She was appointed Director-General of MI5 in 1992. She was the first woman to hold the post and the first Director-General whose name was publicly announced on appointment. Her autobiography, Open Secret, was published by Hutchinson in 2001.