Prince William has said he is "deeply saddened" by the death in Afghanistan of his platoon commander at Sandhurst.
Maj Alexis Roberts was married with two children
Maj Alexis Roberts, 32, from Kent, died in an explosion while returning to Kandahar Airfield on Thursday.
William described Maj Roberts, who served with the 1st Battalion The Royal Gurkha Rifles, as "a good friend".
Maj Roberts is the most senior Army officer to die in Afghanistan since the conflict began. Some 82 UK troops have been killed in the country since 2001.
'Deeply loving father'
A statement issued by Clarence House on behalf of the prince said: "At this time, his thoughts and prayers are with Lex's wife, Susie, their two young daughters, Alice and Freya, and with all his family and friends."
Maj Roberts' wife, Susie, said in a statement: "Lex was my best friend, the most wonderful husband and deeply loving father to Alice and Freya.
"He died doing the job he loved and I had just received a letter from him saying how much good he felt he was doing for the people of Afghanistan and how proud he was to be part of the Royal Gurkha Rifles.
"I am overwhelmed by the support from our family and friends and the positive impact Lex had on people's lives."
Defence Secretary Des Browne said: "I was greatly saddened by the news of Major Roberts' tragic death.
"He was an extremely experienced officer and who was, quite obviously, held in high regard by his superiors, peers and those who worked for him.
"My heart goes out to his family and friends as they come to terms with their loss."
Maj Roberts was usually an Officer of 2nd Battalion The Royal Gurkha Rifles, although he had been serving in Afghanistan with The 1st Battalion when he was killed.
Maj Roberts, and two soldiers who were injured, were taking part in an operation in Helmand Province when they were hit.
Maj Roberts' commanding officer, Lt Col Jonny Bourne, said: "In Major Lex Roberts, both battalions of the Royal Gurkha Rifles have lost a dear friend and a treasured officer.
"The British Army has lost one of its finest prospects and the nation has lost a dedicated servant, a demonstrably warm-hearted man of profound integrity and courage - quite simply, a very special human being."