Theresa May began her political career in the middle of Margaret Thatcher's premiership and has long been touted as the woman most likely to become Britain's second female prime minister.
The long-time darling of the Tory grass-roots has earned a reputation as a tough and experienced political operator with a thick skin and traditional conservative views, with only her trademark bold choice of footwear hinting at a wilder side.
Video report by ITV News Correspondent Julie Etchingham.
Upbringing and tragedy
The vicar's daughter, an only child, was born in Eastbourne in 1956 and educated in both public and private education before heading to Oxford, where she met her future husband Philip and danced to the hits of her beloved Abba.
May studied geography before beginning her career in finance, first at the Bank of England, but suffered personal tragedy with the death of both her parents within the space of a few months in 1981.
Her father Rev Hubert Brasier was shockingly killed in a car crash and her wheelchair-bound mother Zaidee died after battling multiple sclerosis.
It would be a few years before May embarked on her chosen career.
She entered politics via the local council in the London borough of Merton in the mid 1980s but would wait until 1997 before entering Parliament as the opposition's member for Maidenhead.
Quick rise in Parliament
May was quickly promoted to prominent roles within the party.
She oversaw the shadow portfolios for education, employment, work and pensions and House of Commons leader, while also briefly serving as the Conservative's first female chairman.
The coalition's election in 2010 saw May installed as Home Secretary, as she became only the the fourth woman to occupy one of the four great offices of state.
At home making enemies
Her six year run in the department - the longest for more than 50 years - saw her establish her reputation as a tough politician happy to make enemies in pursuit of government policy.
She proved combative with the police force with a memorably attacking speech at the Police Federation's annual conference in 2014 and consistently spoke out against the European Convention on Human Rights.
May survived criticism for failing to deliver on her government's pledge to reduce immigration levels and despite being an ever-present in Cabinet, maintained a political distance from the power base of David Cameron and George Osborne without rocking the party boat.
Seeing off her rivals
Many had tipped May to face Osborne and Boris Johnson in a future race for leader before the EU referendum and aftermath blew the latter two's expected candidacies apart leaving her as the candidate to beat.
Three challengers fell before Andrea Leadsom's shock withdrawal from the race to replace Cameron propelled May towards power.
Her automatic installation means Conservative party members will not get the chance to officially endorse the 59-year-old May as their choice of leader.
But they would have been expected to echo the overwhelming support she received from her party colleagues.
Making the Brexit pledge
The pro-Remain May has vowed to unite those divided by the EU referendum but may be tested on her aim to wait until 2017 before triggering Article 50 to begin the country's formal exit.
She has been unequivocal about honouring the result of the May vote, though.
"Brexit means Brexit," May said. "The campaign was fought, the vote was held, turnout was high and the public gave their verdict. There must be no attempts to remain inside the EU, no attempts to rejoin it through the back door and no second referendum."
'A bloody difficult woman'
Only last week she received a backhanded endorsement of sorts from the now-backbench former chancellor Ken Clarke as his chat with fellow Tory grandee Sir Malcolm Rifkind was accidentally caught on camera.
"Theresa is a bloody difficult woman but you and I worked with Margaret Thatcher," Clarke said, adding "she is good" though doubting her knowledge of foreign policy.
May's prepared response underlined her experience and ambition.
"Ken Clarke might have found me to be a 'bloody difficult woman'. The next person to find that out will be (President of the European Commission) Jean-Claude Juncker."