In a tribute to his late mother, King Charles III led Wednesday’s procession behind the gun carriage carrying her coffin to Westminster Hall.
The Archbishop of Canterbury conducted a short service following the coffin’s arrival.
The late monarch will lie in state in the ancient venue until early on Monday morning.
Those wishing to pay their respects will be able to file solemnly past Queen Elizabeth II's coffin 24 hours a day from 5pm on Wednesday until 6.30am on the day of the funeral – September 19.
Senior royals are also expected to pay their own moving tribute, standing guard at some stage around the coffin – the tradition known as the Vigil of the Princes.
– September 15:
Lying in state continues and a rehearsal is likely to take place for the state funeral procession.
– September 16:
The King and Queen Consort are expected to travel to Wales while lying in state continues.
– September 17–18:
The lying in state continues and heads of state will begin to arrive for the funeral.
Members of the public are invited to observe a one-minute silence at 8pm on Sunday to remember Queen Elizabeth II.
– September 19:
There will be a national bank holiday to allow as many people as possible to watch Queen Elizabeth II's funeral.
Lying in state will continue until 6.30am.
The coffin will be taken in a grand military procession from the Palace of Westminster to Westminster Abbey for the state funeral.
Senior members of the family are expected to follow behind – just like they did for the funeral of Diana, Princess of Wales and the Duke of Edinburgh.
The military will line the streets and also join the procession.
Heads of state, prime ministers and presidents, European royals and key figures from public life will be invited to gather in the abbey, which can hold a congregation of 2,000.
The service will be televised, and a national two minutes’ silence is expected to be held.
After the service, the coffin will be taken in procession from Westminster Abbey to Wellington Arch and then travel to Windsor.
Once there, the hearse will travel in procession to St George’s Chapel at Windsor Castle via the Long Walk, after which a televised committal service will take place in St George’s Chapel.
Later in the evening, there will be a private interment service with senior members of the Royal Family.
Queen Elizabeth II’s final resting place will be the King George VI memorial chapel, an annex to the main chapel – where her mother and father were buried, along with the ashes of her sister, Princess Margaret.
Prince Philip’s coffin will move from the Royal Vault to the memorial chapel to join his late wife's.
Queen Elizabeth II's funeral will take place on Monday
Ian West
King's Guard troops in London on Wednesday
Ben Birchall