Celia Plummer was born in Leicester in 1962/63. She joined the Territorial Army section of the Women's Royal Army Corps as an officer cadet and was commissioned as a probationary second lieutenant on 5 July 1987; her full commission was confirmed the following year. Plummer was promoted to the rank of lieutenant on 5 July 1989. With the disbandment of WRAC and integration of women into the main army Plummer transferred to the Royal Electrical and Mechanical Engineers on 1 April 1991, by which time she held the acting rank of captain. In November of that year she received promotion to the substantive rank of captain with her seniority backdated to 1 January 1991. On 31 July 1993 she married John Attlee, 3rd Earl Attlee, and was afterwards styled Countess Attlee.
Countess Attlee was promoted to the rank of major on 20 January 1997 with seniority backdated to 10 January 1994. She was awarded the Efficiency Decoration for twelve years' service in the TA on 24 August 1999 and promoted to lieutenant colonel on 1 January 2001. From February 2001 to May 2003 she commanded the East MidlandsUniversity Officer Training Corps. She was nominated by her colleagues for appointment as an Officer of the Order of the British Empire, which was approved and granted in the 2003 Birthday Honours. By this time Countess Attlee had divorced Earl Attlee and remarried to John Harvey, a TA colonel 13 years her senior. The couple had their first child in November 2001. Harvey then worked as an instructor at the Joint Services Command and Staff College and was promoted to colonel on 1 March 2005. She was awarded the Queen's Volunteer Reserves Medal in the 2009 New Year Honours and the Volunteer Reserve Service Medal on 23 June 2009. Harvey's husband became a district councillor and in July 2009 Celia Harvey was selected as the Conservative Party's parliamentary candidate for the Leicester West constituency. In the 2010 United Kingdom general election Harvey came second to Labour's Liz Kendall having increased the Conservative vote by 2.8% and reduced Labour's majority to 4,017. Harvey's career outside the army was in academia, particularly in business studies. She has worked as a lecturer and published several papers on innovation and entrepreneurship including Entrepreneurship and Marketing: Issues for Independent Inventors in 2014. Harvey was working as a consultant for Marketwise in 2004. Harvey assists her local branch of the Royal British Legion.
Harvey was promoted to brigadier by 2017, at which time she was serving as assistant commander of Force Troops Command. On 4 June 2019 the then Defence SecretaryPenny Mordaunt announced that Harvey would be promoted to the rank of major general and appointed deputy commander Field Army in March 2020. Harvey would become the third female major general in the British Army and the first from the reserve forces. Harvey assumed the appointment on 11 March 2020. Harvey was promoted to major-general on 11 March 2020.
