LONDON: Theresa May's resignation announcement Friday (May 24) sets the stage for a back-stabbing leadership battle in her Conservative Party that will determine who becomes Britain's next prime minister.
Here is a guide to how the unusual process works.
May said she will officially step down as party leader on Jun 7.
This means she will still head the government when US President Donald Trump visits Britain on Jun 3-5.
She is expected to remain in office until a successor is chosen. Or she might decide that she has had enough and ask someone like her de facto deputy David Lidington to step in a caretaker capacity for a few weeks.
The race itself is broken down into two stages with no defined time limits or unbreakable rules.
The first will see Conservative members of parliament - there are 313 in all - sift through the candidates and whittle them down to two.
The second will see tens of thousands of grass roots party members pick the winner in a secret ballot.
Everyone will hope to get the process over and done with by the end of July.
Britain has little time to waste on a popularity contest because of the danger that it might crash out of the European Union without a plan for moving forward on Oct 31.
READ: Timeline: Theresa May - three tumultuous Downing Street years
But it is a crowded field of hopefuls and declared contenders that some UK papers currently put at up to 18.
A few have realistic shots at heading the government and many are running in the hope of picking up a juicy post in the new cabinet.
And whoever wins takes over what may be one of Europe's hardest jobs.
May has headed a minority coalition government that has been rebuffed by parliament on Brexit and UK politics are in a state of flux.
The new government leader will pick up these pieces once formally appointed by the queen.
The list of contenders is first pared down through a series of votes by Conservative lawmakers in which the last-place finisher is knocked out.
The jockeying for position has already started as hopefuls build coalitions and some join the campaigns of others in exchange for private promises of future jobs.
The ballots themselves have been cast in past contests on Tuesdays and Thursdays.
This means that a field that starts off with 10 names would take a month to sift through.
But Britain is facing a doomsday Brexit deadline and the whole thing could be sped up by the committee that sets the party's rules.
The eventual winner is chosen by Conservative Party members of at least three months' standing across Britain.
They mail in their ballots after listening to the two finalists debate each other across various venues over the course of a few weeks.
May skipped this stage because her rival Andrea Leadsom withdrew after giving an unfortunate interview for which she was widely condemned in which she suggested May was less qualified as a leader because she had no children.
Yet Britain's political scene is in spasms and few would dare predict how the whole thing turns out.
Conservative lawmakers will be torn between picking someone genuinely popular with the public and someone who reflects their own views on future ties with the EU - the sole issue at play today.
The odds-on favourite is Boris Johnson - an affable ex-mayor of London and former foreign minister whose cosmopolitan views are tinged with a particular distaste for Brussels.
He is widely seen as the Conservatives' answer to the surging Brexit Party of anti-EU populist Nigel Farage.
But the makeup of the broader party that picks the eventual winner is both older and more conservative than the British public surveyed by opinion polls.
It might take a more sceptical view of Johnson's perceived social liberalism and select someone more traditionally conservative such as former Brexit secretary Dominic Raab.
And UK conventional wisdom says that the most popular or likely candidate almost never ends up getting the top Conservative Party job.
The history of underdogs knocking out the frontrunner dates back to the current system's introduction in the post-war era and continues to this day.
It includes May's victory over Johnson - the favourite in 2016 as well - and the rise of her predecessor David Cameron over party darling David Davis.