Dame Cressida holds the title of the UK’s most senior police officer, after more than 30 years in uniform.
Originally from Oxford Dame Cressida was educated at the city’s university, graduating from Balliol College.
She joined the Met in 1983, where she served as a constable, sergeant and inspector in central south-west and south-east London.
In 1995 she transferred to Thames Valley Police as superintendent operations at Oxford, and subsequently spent three years as area commander.
She took a career break to study for a Master’s degree in criminology at Cambridge University, before returning to the Met in June 2001.
Dame Cressida, who was the UK police lead for hostage negotiation, was appointed director of the force’s diversity directorate and head of the racial and violent crime taskforce before moving to the specialist crime directorate in 2003.
During her second stint at the Met she took on command roles in the police response to the 9/11 attacks and the Boxing Day tsunami in 2004.
She was thrust into the public eye in 2005 after she was in charge of the operation that led to the fatal shooting of Brazilian Jean Charles de Menezes who was wrongly identified as a potential suicide bomber.
A jury later cleared Dame Cressida of any blame in his death.
In February 2007 she was promoted to deputy assistant commissioner and was made the Met’s first female assistant commissioner in 2009.
She was the national lead for counter-terrorism for three years, and also led the security operations for the Queen’s diamond jubilee and 2012 Olympics.
Her work also included leading the re-investigation into the murder of Stephen Lawrence and the police response to the killing of Lee Rigby.
Dame Cressida then left Scotland Yard in January 2015 to become a director-general at the Foreign Office before returning as commissioner in 2017.
She was made a dame in Theresa May’s resignation honours in 2019.
Speaking on BBC Radio 4’s Desert Island Discs the same year, she said her image was “a bit different” and had encouraged young people from different backgrounds to consider applying to the force.
Dame Cressida is gay but has said her sexuality is “one of the least interesting things” about her, adding: “I happen to love Helen, she’s my partner, on we go.”
Thought to be well-liked among the rank and file, Dame Cressida shared an anecdote that her colleagues are very amused that she cannot detect the smell of cannabis.
She stepped into the role of commissioner in the aftermath of the Westminster terror attack, in which Pc Keith Palmer was stabbed to death as he carried out his duties on March 22, 2017.
The Met has continued to face criticism over the relationship between police and black Londoners.
Dame Cressida has denied the force is institutionally racist but has admitted her force “is not free of discrimination, racism or bias”, but has a zero-tolerance policy.
The force faced controversy and accusations of alleged racial profiling following a series of high-profile incidents filmed and shared online.
Dame Cressida apologised and launched a review into the use of handcuffs pre-arrest after the vehicle stop of Team GB athlete Bianca Williams last July.
In another incident in August 2020, Labour MP Dawn Butler accused police of racially profiling her after a vehicle she was travelling in was pulled over in error for questioning.
Dame Cressida has repeatedly defended the use of stop and search powers to take hundreds of weapons a month off London’s streets.
Dame Cressida has also faced criticism over her role in the Met’s bungled investigation into false claims of a VIP sex abuse ring in Westminster.
The allegations of fantasist Carl Beech, then known as “Nick”, led to an investigation called Operation Midland between 2014 and 2016.
Dame Cressida had been responsible for supervising the senior investigating officer who said allegations made by Beech, which were subsequently shown to be false, were “credible and true”.
In October 2019, she made a public apology for mistakes in the police investigations.
Two months later, Dame Cressida was referred to the Independent Office for Police Conduct (IOPC) but was later cleared.
After months of nationwide questions over policing in the pandemic, the head of the Met is now facing wide criticism over her force’s actions at the vigil on Saturday, but has defied calls to quit.