The starting pistol has been fired on the race for Downing Street.
The process isn't straightforward - with several rounds of voting before the next Prime Minister of the United Kingdom is elected.
We take a look at how it works.
What happens now?
Candidates must submit nominations by 5pm on June 10 with a shortlist to follow soon after.
Successful nominees need a proposer, seconder, and the support of six other MPs.
Ok, so who is running?
As of Monday afternoon 11 candidates indicated they intended to run.
How do we get from 11 to one?
On Thursday Conservative MPs will vote from 10am to noon - candidates hoping to make it to the second round must secure the vote of 17 MPs (5% of Tory seats).
However, if each candidate receives 17 votes the nominee with the lowest number is eliminated.
And then what?
Candidates who make the second round must then secure 33 votes, again if all candidates receive the backing of 33 MPs the nominee with the lowest number will be eliminated.
Voting continues until two candidates remain - a third vote would take place on June 19, with further votes pencilled in for June 20.
Do other party members get a say?
Yes. Ballot papers are sent out to party members the week beginning June 22.
Just two candidates will be on the ballot paper making the contest a straight head to head.
Are there going to be any public events?
So far Rory Stewart has been touring the country to meet voters to hear their concerns, showcasing his trips with awkwardly filmed videos.
And on Monday Matt Hancock, Dominic Raab and Michael Gove launched their campaigns.
There will be televised debates on Channel 4 on June 16 and on BBC One on June 18.
Read more from Yahoo News UK
When will the winner move in to Downing Street?
Parliament breaks for recess on July 20 with the leadership results announced two days later on July 22.
The leader, in theory, could move belongings to the small flat upstairs immediately but realistically they will not formally begin their duties as prime minister until September 5 unless Parliament is recalled.
And what about the losers?
There are some complicated relationships among the contenders, none more than Michael Gove and Boris Johnson.
In 2016 Gove was due to be Boris’ campaign manager but withdrew on the day of nominations and instead announced his own intention to run.
If Boris emerges victorious it is unlikely Gove will earn a cabinet place but some lower profile candidates have been accused of using the contest to showcase themselves in a bid to earn a cabinet position.
It is likely some of the candidates will feature in the winner’s cabinet - as many have held prominent positions since the Coalition government in 2010 but in reality what happens after July 22 depends on the next few weeks.