More than 1,000 troops and 200 horses were on the streets of London during the early hours of Friday morning.
Around 1,300 personnel were involved, preparing for their major role in the State Opening of Parliament ceremony on Monday 14 October.
Household Cavalrymen and Gunners from the King’s Troop Royal Horse Artillery assembled at 3am on the Wellington Barracks parade square in Westminster to rehearse their roles on the empty roads.
On Monday, the Army’s Household Division will be among military personnel ready to line the streets and escort the Crown Jewels and Her Majesty The Queen’s procession from Buckingham Palace to the House of Lords.
A 41-gun salute will be fired from Green Park when the Queen arrives at the Palace of Westminster, and then at the Tower of London at the moment she leaves, having delivered The Queen’s Speech.
The State Opening marks the formal start of the next parliamentary session.
The primary purpose of the tradition is to set out the Government's legislative agenda to both Houses of Parliament in the Queen's Speech.
There will also be musical accompaniment from The Band of the Royal Marines, The Band of the Household Cavalry, The Band of the Coldstream Guards, The Band of the Scots Guards, The Band of the Welsh Guards and the Band of the Royal Air Force.
Many of the units taking part were involved recently in operational deployments to Iraq, Afghanistan, Estonia, Georgia, South Sudan, Malawi and Falkland Islands.
Troops involved are also preparing for Remembrance week in early November, in particular, the National Act of Remembrance at the Cenotaph, The Lord Mayor’s Show, and the Festival of Remembrance at the Albert Hall.