Trained by Tom Taaffe, Kicking King enjoyed six Grade One wins over fences in all, with his brilliant victory in the 2005 Gold Cup sandwiched by back-to-back successes in the King George VI Chase at Kempton and Sandown respectively.
He spent over two years on the sidelines with a tendon injury following the latter victory and having failed to rediscover his best form, he was retired in 2008 and took up residence at the Irish National Stud alongside other 'Living Legends' including Hardy Eustace, Hurricane Fly and Faugheen.
"Kicking King was a natural, athletic horse with balance – a great horse for Conor Clarkson (owner), Barry Geraghty and all our staff," said Taaffe, speaking on the stud website.
"He was an ambassador for racing and was fortunate to have a second life in the exceptional care of the Irish National Stud.
"He gave the Taaffe family many special moments, but I particularly recall the day he won the John Durkan Chase at Punchestown. John was a great friend to us all and that day Kicking King put up a special performance of jumping and galloping.
"The Gold Cup was what you dream of. We were lucky to have him."
Geraghty rode Kicking King in all but two of his 28 career starts.
"It is very sad news to hear Kicking King has passed away. He was a real star, a big powerful horse who loved his racing," he said.
"He provided me, Conor Clarkson and Tom Taaffe with some special days. He put in brilliant performances winning the Gold Cup and two King Georges and gave us many more great days to remember.
"As a family we enjoyed visiting him in the National Stud where he had a lovely retirement and was so well cared for by everyone, especially Leona Harmon."
For Clarkson, Kicking King was the horse of a lifetime. He said: "Kicking King brought my family, friends and I on an odyssey in horse racing few are privileged to enjoy.
"My thanks to Tom Taaffe and his team for their magnificent handling of Kicking King that enabled him with the wonderful Barry Geraghty on board to achieve so much.
"I am so pleased that he spent so many happy years providing enjoyment to the public in the unparalleled care of the Irish National Stud."