A parade of hundreds of British military personnel were up late on Monday night rehearsing the route for the ceremonial procession of King Charles III and Queen Consort Camilla’s coronation.

In under three-weeks’ time, the 2.1km route will be lined with thousands of spectators hoping to catch a glimpse of the formally crowned monarchs.

King Charles and Camilla were not present for the rehearsal, nor were the carriages that will take them from Buckingham Palace to Westminster Abbey and back again.

They will be taken to Westminster Abbey in the Australian-made Diamond Jubilee State Coach and will then return through the same route in the 260-year-old Gold State Coach.

Dressed in military attire, the cavalcade practised its route to and from Westminster Abbey via Parliament Square, along Whitehall, around Trafalgar Square, through Admiralty Arch and along The Mall and the end of which stands Buckingham Palace.

About 400 armed forces personnel from at least 35 Commonwealth countries including Australia will join the procession of around 6,000 representatives of the British military on the day.

Both the ceremony and the procession route will be shorter than Queen Elizabeth II’s in 1953.

For the late Queen, the coronation ceremony lasted almost three hours, with over 8,000 official guests seated in temporary tiers in Westminster Abbey.

This time, the palace has confirmed it has invited 2,000 guests, for an hour-long service.

Queen Elizabeth II’s procession travelled 8km through Piccadilly, Oxford Street and Regent Street, which took two hours and featured tens of thousands of representatives.

The coronation of King Charles and Queen Camilla will take place on May 6.

ABC/ wires