The Queen met soldiers and horses when she visited Combermere Barracks in Windsor ahead of the state visit of the Emir of Kuwait to Windsor on Tuesday.
Dressed in a long violet coat with a matching hat, she met several soldiers from the Household Cavalry Regiment and Cavalry Mounted Regiment.
She saw soldiers cleaning and preparing items of uniform, and petted the drum horse, which will be on official duty for the first time at the visit.
The drum horse was renamed Adamas, which means Diamond in Greek, in commemoration of the Queen's Diamond Jubilee.
The Queen then took a tour of the training school where she saw a riding lesson being undertaken by 19-year-old Trooper Thomas Ephgrave, from Leatherhead in Surrey.
She asked Trooper Ephgrave, who has been learning to ride for four weeks after joining the Army in March, about his horse, which is named Elizabeth after her and is often ridden by the Princess Royal at the Queen's Birthday Parade each June and was impressed when told he had always wanted to join the Army.
The Queen also seemed intrigued when shown armoured fighting vehicles which were at the forefront of Britain's military operations in the Falklands, Bosnia and more recently in Iraq and Afghanistan.
She asked soldiers about their families and their time in Afghanistan.
She then took part in a photograph with 875 members of both regiments.
Combermere Barracks is less than a mile from Windsor Castle and dates back to 1804. The riding school was built in 1881.