Theresa May will succeed David Cameron as British prime minister on Wednesday, having served as home secretary for six years - the longest-serving politician to hold that post in the country's recent history.
The 59-year-old is relatively unknown internationally, while at home she is often described as a tough negotiator. During her tenure in the home office, media reports often referred to May as "steely", "single-minded", and even "ruthless".
May outmanoeuvred all other contenders to the position of the leader of the ruling Conservative Party, simply by outlasting rivals as they imploded around her in the wake of Britain's vote to leave the EU - including former London Mayor Boris Johnson, who led the Brexit campaign, as well as his one-time Brexit ally, Justice Secretary Michael Gove.
Most recently, Energy Minister Andrea Leadsom pulled out of the leadership contest following criticism of comments she made in a newspaper interview about May and the experience of motherhood as an important quality for a prime minister. May does not have any children.
So, who is May and where does she stand on key issues such as Britain's EU membership, freedom of movement and human rights?
May is probably best known for her tough stance on immigration as home secretary, including efforts to cut net migration numbers such as barring British citizens from bringing spouses and children into the UK unless they earn in excess of £18,600 ($24,000).
One study estimated that 15,000 children had been affected by the minimum income requirement since its implementation in 2012.
"Many parents are suffering from anxiety and depression as a result of the separation and the pressure of meeting the financial threshold. This also directly impacts their children," said the Joint Council for the Welfare of Immigrants, who carried out research on the issue with Middlesex University.
The Divided Families Campaign accused May of making family reunification "a privilege for only the wealthy" and "turning the Universal Declaration of Human Rights on its head" as it pertains to families and home life.
In April, the home office introduced hefty new earnings thresholds for non-EU citizens who want to live in Britain. Those living in the country for less than 10 years now need to earn at least £35,000 (46,000) a year if they want to settle permanently in the UK. Nurses are among the few who are exempt from the rule.
An online petition against the new charges said the fee hike "discriminated against low-earners" and Britain would lose thousands of skilled workers as a result. The petition has more than 114,000 signatures.
Freedom of movement
The daughter of a Church of England vicar, May studied geography at Oxford University, joining the Bank of England after her studies.
She worked as a financial consultant at the Association for Payment Clearing Services before becoming a politician for Maidenhead, west of London, in 1997.
She became chairman of the Conservative Party in 2002, famously telling supporters at its conference that year that people saw them as "the nasty party".
Following last month's referendum vote, May has not clarified whether "she believes the rights of EU citizens living in the UK should be protected", Al Jazeera's London correspondent Laurence Lee said.
She has said, however, that the EU ideal of freedom of movement could no longer prevail in post-Brexit Britain.
"I'm very clear that the Brexit vote gave us a very clear message from people, that we couldn't allow freedom of movement to continue as it had done hitherto," May said.
"We need to bring control into movement of people coming into the UK from the EU ... Still I believe we should have that goal of bringing immigration down to sustainable levels."
Controversially, May hinted in April that she might move to withdraw Britain from the European Convention on Human Rights (ECHR), which she said bound the hands of the British parliament in its ability to enforce laws, particularly the deportation of foreign criminals.
May scored a victory in 2013 over the European Court of Human Rights with the deportation of Islamic cleric Abu Qatada to Jordan after a 10-year-long legal battle. The Court had initially barred his deportation from the UK owing to concerns he might face torture.
In April, Amnesty International responded to May's comments on withdrawing from the Convention, saying the move would jeopardise the Good Friday agreement, which had brought peace to Northern Ireland.
And at the launch of her party leadership campaign, May said she would no longer seek an ECHR withdrawal as prime minister.
Britain's EU relationship
While she must now take charge of delicate negotiations to separate Britain from the EU, May stayed out of the spotlight during Britain's divisive referendum campaign - and only tepidly backed remaining in the bloc in a single speech.
Al Jazeera's Lee said that even though May was formally against leaving the EU, "many suspected her heart was never really in the European project - particularly its rules on free movement.
"May was almost entirely silent during the referendum" yet now she "seems convinced that Britain is headed for the exit," Lee said. "Now she has to stop the UK from fracturing any further."
May has been more forthright recently on what should take place following the victory for the "Leave" side in the referendum.
"Brexit means Brexit. 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," she said on June 30.
"We have a job to do in making the best deal we can in coming out of the EU and I am very clear that I will deliver Brexit."
Source: Al Jazeera and agencies