Royal Navy reservist Penny Mordaunt was appointed as the first-ever female defence secretary following the sacking of Gavin Williamson in May 2019.
She was in the cabinet post for just 85 days after being removed from the position by then-new Prime Minister Boris Johnson.
Ms Mordaunt had returned to the department after previously working as Minister of State for the Armed Forces from May 2015 until July 2016 and Parliamentary Private Secretary to then-defence secretary Philip Hammond.
First elected to Parliament as MP for Portsmouth North in 2010, Ms Mordaunt achieved ministerial rank under David Cameron between 2014 and 2016 and was appointed Minister for disabled people when Theresa May took power in 2016.
The daughter of a paratrooper-turned-teacher, she serves as acting sub-lieutenant of the Portsmouth-based HMS King Alfred.
In April 2019, the Queen appointed her a commander with an honorary commission before becoming an honorary captain in June 2021.
Watch: Penny Mordaunt promoting the role of women in the Armed Forces in 2016.
Her voting record on defence:
Voted against an investigation into the contrast between public statements and private actions in the run-up to the Iraq war.
Consistently voted for use of UK military forces in combat operations overseas.
Consistently voted for replacing Trident with a new nuclear weapons system.
Consistently voted against strengthening the Military Covenant.
Consistently voted for military action against the so-called Islamic State.
2 May: Taking the post
Ms Mordaunt took over from her predecessor Gavin Williamson, having previously served as Minister for International Development.
She had previously worked as Minister of State for the Armed Forces from May 2015 until July 2016 and Parliamentary Private Secretary to then-defence secretary Philip Hammond.
3 May: First Official Engagement
Alongside the Duke of Cambridge, the former Defence Secretary attended her first service as the Defence Secretary, having just taken the role one day before.
They heard of the pride and sacrifice that has gone into delivering five decades of Britain's continuous at-sea nuclear deterrent.
12 May: Mental Health Support For Veterans
Ms Mordaunt announced a new package of measures to boost mental health support for ex-service personnel.
Up to £9m funding was put towards veterans' mental health and wellbeing activities. It followed the Government’s allocation of £10m to support veterans' mental health.
24 May: Encouraging Women Into The Armed Forces
By 2028, Ms Mordaunt said women should make up at least 15% of UK personnel on UN peacekeeping missions.
She also announced that at least 6% of patrol personnel in Cyprus should be women.
6 June: D-Day 75 Commemorations
Ms Mordaunt travelled to Arromanches-les-Bains, Normandy to attend commemorations marking 75 years since the D-Day landings.
Speaking at the event, she said it was an example of how we can learn "from nations coming together and working with others in order to achieve good things".
26 June: First Visit To NATO HQ
The annual Defence Ministers meeting saw both Ms Mordaunt and the then-US Defense Secretary Mark Esper, showing a united front as they both attended the meetings in Brussels for the first time.
On the agenda was Iran, the INF treaty, NATO's rapid reaction readiness force and a new space policy.
29 June: Armed Forces Day
For Ms Mordaunt, it was her first and only Armed Forces Day event as Secretary of State for Defence.
Watch: Penny Mordaunt attended her only Armed Forces Day as Defence Secretary in 2019.
6 July: Pride in London
While Ms Mordaunt had attended Pride events before, this was her first one with the military.
During the event, she paraded through Trafalgar square with personnel.
18 July: New space planfor the UK
Having said "the sky is no longer the limit" Ms Mordaunt announced a new space plan for the UK to adapt to "evolving threats".
£30 million will be invested to fast-track the launch of a "small satellite demonstrator" within the next year.
22 July: Mali deployment
Ms Mordaunt announced that the Armed Forces will deploy to Mali in 2020 to support the UN peacekeeping operation.
A total of 250 personnel will deploy to Gao, Eastern Mali, as a response to the increasing instability in the Sahel region.
24 July: Penny Mordaunt leaves Cabinet
In a tweet, Ms Mordaunt said: "I'm heading to the backbenches from where the PM will have my full support, as will my successors at the MOD and Women Equalities.
"Thank you to everyone who's helped me get things done, especially our Armed Forces and civilians in defence for the last 85 days.
"We achieved much."