As the newly promoted Home Secretary, Theresa May becomes only the second woman after Jacqui Smith, to hold the role - considered one of the three major offices of state.
In opposition she most recently held the position of shadow work and pensions secretary, plus shadow women's minister - the latter a brief she will now continue to fulfil in Government.
Previously shadow Education and Employment Secretary in the William Hague front-bench line-up, she became shadow Secretary of State for Transport, Local Government and the Regions, before becoming Tory party chairman in 2002.
Mrs May, 53, later held the positions of shadow Secretary of State for the Family, including Culture, Media and Sport in 2005, and shadow Leader of the House of Commons between 2005 and 2009.
A former City high-flyer, Mrs May opposed Labour's all-women short-lists and claims that all her political achievements are the result of her own efforts and abilities, insisting that gender is irrelevant.
She co-founded Women2Win to assist in training females to become Tory parliamentary candidates.
Her political career has not been a totally smooth ride. As party chairman she told the conference one year that the Tories were no longer the "nasty party", implying, to the fury of many of her colleagues, that they once were.
Mrs May, a vicar's daughter, was educated at Wheatley Park Comprehensive School and read Geography at St Hugh's College, Oxford.
She has a wealth of banking experience, as a Bank of England executive officer from 1977 to 1983 and a consultant for the Inter-Bank Research Organisation from 1983 to 1985, when she became head of the European Affairs Unit at the Association for Payment Clearing Services, until 1996 and Senior Adviser on International Affairs between 1996 and 1997.
Meanwhile, her political career was starting to blossom. She was a councillor on Merton Borough Council from 1986 to 1994, and unsuccessfully fought two parliamentary seats during that period, Durham North-West in 1992 and Barking at a 1994 by-election.
She was finally elected for the new seat of Maidenhead in May 1997.
While at Merton, she was chairman of the local education committee, something which almost certainly prompted Mr Hague to give her that portfolio in 1998.
Although not a flamboyant figure, Mrs May made her mark in that job. At the 1999 Conservative Party conference she promised "a bonfire of controls" to free schools from "the dead hand of local authorities".
On the Conservative Party website, she lists her proudest political achievement as bringing a minor injuries unit to St Mark's Hospital in Maidenhead and her interests as walking and cooking.
Mrs May is also known for her fondness for shoes after wearing a pair of leopard-print kitten heels to a Conservative Party Conference.