Britain will have a new Prime Minster today.
David Cameron will formally tender his resignation to the Queen and Theresa May will step in to 10 Downing Street.
But how will the day unfold? Here's everything you need to know:
- Prime Minister's Questions
Prime Minister David Cameron will leave 10 Downing Street on Wednesday morning for the House of Commons, where he will face his final PMQs from midday.
It is expected to be a more relaxed session than usual, with members likely to applaud Mr Cameron at the end.
Labour leader Jeremy Corbyn will once again take to the Dispatch Box opposite Mr Cameron, but this time knowing that he will face a leadership election.
- David Cameron will tender his resignation
After PMQ's, David Cameron will make the short trip from Parliament to Buckingham Palace for an audience with the Queen.
He will formally tender his resignation, and will recommend that Theresa May - as leader of the largest party in the House of Commons - should be invited to form a government.
With the formalities out of the way, David Cameron will leave Buckingham Palace.
- Who will run the country once David Cameron resigns?
At this point, the UK will not have a Prime Minster.
For the interim period, the country will be managed by Cabinet Secretary Sir Jeremy Heywood.
- What happens next?
Theresa May will be summoned to Buckingham Palace by the Queen and invited to form a government - it will be the 13th time Her Majesty has performed such a duty.
In keeping with tradition, Mrs May will "kiss hands" (in reality, shake hands) with the Queen.
She will then be appointed as the country's second female Prime Minister and depart for 10 Downing Street, from where she will address the nation.
- When will Theresa May announce her government ministers?
It is expected Theresa May will make an announcement on her key appointments later on Wednesday afternoon.
- Where will David and Samantha Cameron go?
Their London home in North Kensington is reportedly already being rented, so it's possible they'll move to his constituency home in Oxfordshire.
Larry the cat, however, will be staying in Downing Street.