The Queen’s coffin has arrived at Westminster Hall accompanied by her family.
A ceremonial procession departed Buckingham Palace shortly at 2.22pm where the late monarch had been lying in been rest since travelling from Scotland for the last time on Tuesday.
Members of the Royal Family, including King Charles III, William, Harry, Anne, Edward and Andrew walked with the procession to Westminster Hall.
People had lined The Mall and streets along the route to witness the historic moment.
The procession travelled through Queen’s Gardens, The Mall, Horse Guards and Horse Guards Arch, Whitehall, Parliament Street, Parliament Square and New Palace Yard.
There was a gun salute at Hyde Park as the procession made its way to the Palace of Westminster, where it arrived shortly after 3pm.
The Queen will lie in state in Westminster Hall until her funeral on September 19.
Tens of thousands of people are expected to queue to pay their respects to the late monarch in London.
A five-mile line is set to open at 5pm, but some mourners began their wait as early as Monday.
There has been a suggestion that the number of people allowed into the hall could be capped at around 350,000 over the four day period.
The queue will begin on Albert Embankment next to Lambeth Bridge, before running down the River Thames to Southwark Park.
Additional toilets and water fountains have been placed along the route, with cafes and local businesses also expected to extend their opening hours.
More than 1,000 volunteers, stewards and police officers will be on hand to support those in the queue.
Inside Westminster Hall, the coffin will be raised on a catafalque and draped in the Royal Standard, with the Orb and Sceptre placed on top.
It will be guarded around the clock by a vigil of units from the Sovereign’s Bodyguard, the Household Division, or Yeoman Warders of the Tower of London.