A message of condolence, signed by Elizabeth R, was shared on the Royal Family’s Twitter page.
The tweet read: “I was saddened to hear of the death of His Highness Sheikh Sabah Al Ahmed Al Jaber Al Sabah.
“Your distinguished brother devoted his life to the service of the State of Kuwait and especially its relationship with its allies and friends.
“He will be long remembered by all who work for regional stability, understanding between nations and between faiths, and for the humanitarian cause.
“I have deeply valued his friendship towards the United Kingdom, and his memorable State Visit in November 2012.
“I offer Your Highness my sincere condolences.
“I offer also my sympathy to the people of Kuwait. May the long history of close companionship between our two families continue.”