Led by the Queen and Prince Philip, the royal family celebrated 200 years of Gurkha service with the British Army at a spectacular parade showcasing the best of their history and culture.
Prince Harry was on his usual charming form, chatting with dancers in traditional dress and even breaking his own 'no selfie rule' to take a picture with one attractive young lady.
The Queen is accompanied by the Sultan of Brunei (left) who has been protected by Gurkhas since 1974
However, if the limelight was very firmly on the royal matriarch and her husband there was a special reason – it was the eve of Prince Philip's 94th birthday on 10 June. The doughty former naval officer seemed to thoroughly enjoy the occasion, joking with other veterans.
The only concession to his advancing years was a long black coat to ward off the evening chill. At the Diamond Jubilee River Pageant three years ago he became ill after standing for several hours in the cold. So at Tuesday's event he had wisely wrapped up.
The Queen, who has had as full an agenda as ever with the recent State Opening of Parliament, was full of smiles and looking elegant in an Angela Kelly silver and white coat. As a keen amateur historian of military affairs, she will have appreciated the battle reenactments that formed part of the entertainment.
Prince Harry breaks his 'no selfie' rule for a Nepalese dancer
In their two centuries of service the Gurkhas, who hail from Nepal, have gained a reputation for loyalty, their indomitable fighting spirit and skills with kukri knives, their weapon of choice. Some 26 of them have been awarded the British Army's highest honour, the Victoria Cross.
One of those the royal couple met was 76-year-old Captain Rambahadur Limbu, the only surviving Gurkha recipient of the Victoria Cross. He told his hosts: "It is my great privilege to meet the highest members of the British royal family. I am, as you say in England, over the moon."
Some 1,400 guests enjoyed the festivities at the Royal Hospital Chelsea
Amid the festivities there was a sombre note as a minute's silence was held to remember the 8,000 victims of the Nepal earthquake on April 25.
Prince Charles in his capacity as patron of the Gurkha Welfare Trust paid tribute to those who had lost their lives.
"The Brigade of Gurkhas is more than just a fighting force, it is also – in every sense of the word – a family," said the future King. "As with every family, they have lifetime responsibilities to one another and especially in times of great need.
"This has been painfully illustrated by the appalling earthquakes which have recently struck Nepal, with devastating consequences across the traditional Gurkha heartlands.
"As part of the wider Gurkha community, we share in these responsibilities and I am constantly humbled by your ongoing support."