The Royal Family will reunite tomorrow as part of the Queen's coffin procession as it makes its way from Buckingham Palace to Westminster Hall.
At around 2.20pm, the coffin will be taken in procession by gun carriage from Buckingham Palace to the Palace of Westminster.
King Charles will lead the procession, followed by Prince William and Prince Harry who will walk behind their grandmother's coffin, along with the Duke of York, the Princess Royal and the Earl of Wessex - who will all follow the coffin on foot as it makes its journey to Westminster Hall.
Anne's son Peter Phillips and her husband Vice Admiral Sir Tim Laurence will also walk in the procession, as well as the Duke of Gloucester and the Earl of Snowdon.
Follow all the latest updates on the Queen's funeral arrangements and laying in state here
The Queen Consort, the Princess of Wales, the Countess of Wessex and the Duchess of Sussex will travel by car.
The royals will be joined by 500 members of the military - all moving at a slow and sombre pace as drummers beat 75 beats a minute – something that is proving a challenge for the horses.
Sgt Tom Jenks, 30, who is riding the lead horse in front of the gun carriage that will be pulling the coffin, told the Guardian : “It’s quite a tall order to ask them to walk at a slow march pace.
"Any of our normal parades it’s a natural horse walking pace, which is a bit more forward-going than human pace, so we’re asking them to half that again."
His horse, Cassius, will be retiring after the parade after 12 years’ service - during which time he has covered Margaret Thatcher’s funeral.
The coffin is expected to arrive at the Palace of Westminster at 3pm where the Archbishop of Canterbury will conduct a short service.
After this, the Queen's lying in state will begin in Westminster Hall, lasting four full days.
During this time, thousands of people are expected to file past the coffin to pay their respects to the late monarch.
Senior royals are also expected to give their own tributes, with some standing guard around the coffin in a tradition called the Vigil of the Princes.
The Queen's lying in state will continue for four days from Thursday, September 15 to Sunday, September 18.
A rehearsal for the state funeral procession is likely to take place on Thursday.
Once the lying in state ends on Sunday, heads of state are expected to begin arriving in the UK for the funeral.