The Queen and the Duke of Edinburgh will today watch as thousands of troops parade through Windsor in celebration of the Diamond Jubilee.
Some 2,500 troops from the Royal Navy, the Army and the Royal Air Force will parade through the Quadrangle of Windsor Castle then through the town, together with a tri-service Guard of Honour and six military bands.
The Queen and Philip will then travel along the same route before watching a tri-service flypast of 78 aircraft, including helicopters, Hawks, the Battle of Britain Memorial Flight, the Red Arrows and Tornados.
Chief of the Defence Staff General Sir David Richards said: "Her Majesty the Queen's support and encouragement over the years has created a very special bond between our monarch and her forces.
"That link is felt by all those who have the privilege to wear Her Majesty's uniform both in the UK and on many varied operations overseas.
"The parade and muster will truly be a day to remember. It is an opportunity to highlight the unique relationship the Queen has with the men and women of the Armed Forces and of the role she fills in our lives."
A Royal Air Force Merlin will be leading the fly past, heading up a 12-helicopter formation.
The lead pilot, Wing Commander Jason Appleton from RAF Benson, Oxfordshire, said:
"It is an absolute honour, a once in a lifetime opportunity to be the first of 78 aircraft saluting the Queen.
"We routinely work with the Army and Navy as a part of Joint Helicopter Command in the UK and on Operations around the world such as Afghanistan, so in that sense it is business as usual.
"My little boys will be watching out for me on the TV at home so I had better make sure we are on time."
The Queen will make a speech before a performance of specially-composed music. She and the Duke of Edinburgh will then attend a number of receptions.
The royal couple will be joined by the Duke of York, Princesses Beatrice and Eugenie and the Earl and Countess of Wessex.
ITV Meridian were filming with the Coldstream Guards in Windsor this morning, preparing to be the Guard of Honour for the Queen's Jubilee celebrations in Windsor today. More than 2,500 troops will parade through the town. Crowds of up to 30,000 people are expected.