Legendary former Wales and British and Irish Lions captain and coach John Dawes has died at the age of 80.
Dawes won the first of his 22 Wales caps in 1964 and was captain six times, leading them to the Grand Slam in 1971.
He also captained the Lions on the 1971 tour of New Zealand, still the Lions' only series win over the All Blacks.
As coach of Wales, Dawes won four Five Nations titles including two Grand Slams and four triple crowns and was coach of the 1977 Lions in New Zealand.
The Lions tweeted on Friday: "We are deeply saddened to hear of the passing of Lion #487 John Dawes.
"Captain of the Lions on the 1971 Tour, the only Lions side to win a series in New Zealand, Dawes made 19 appearances for the Lions.
"A true legend of the game, John will be sorely missed."
Dawes' first club Newbridge said: "After a period of ill health, John Dawes sadly passed away this morning.
"Everyone associated with our game will be aware of John's story and his great achievements.
"His venture into senior rugby started with us here at the Welfare Ground.
"The heartfelt condolences of everyone at Newbridge RFC go out to John's family at this very sad time."
London Welsh described him as "the heart of our great club for over 50 years."
After starting his career at Newbridge, Dawes went on to captain and coach the London Welsh team of the late 1960s and early 1970s which included future Wales captains Mervyn Davies and JPR Williams as well as flanker John Taylor and wing Gerald Davies.
A skilful and astute centre, Dawes led a Wales team including all of those Exiles to the Five Nations Grand Slam in 1971.
He then captained the Lions for their tour of New Zealand the following summer, leading them to a 2-1 series win which remains the only time the Lions have beaten the All Blacks in a Test series.
Dawes also captained the Barbarians in their 1973 victory over New Zealand in Cardiff, best remembered for Gareth Edwards's "try of the century" with Dawes playing a key role in the build-up.
Within a year Dawes was appointed Wales coach and he presided over a period of domination, winning the Five Nations championship four times between 1975 and 1979, including two Grand Slams and four consecutive Triple Crowns.
Dawes was also appointed coach of the Lions for the tour of New Zealand in 1977, but this time the All Blacks won 3-1.
"He was truly outstanding player," former Wales fly-half and team-mate Phil Bennett told BBC Radio Wales.
"He wasn't the fastest but what he had was a brilliant rugby brain.
"Great players have time and John always had time, always knew when to pass the ball or put a grubber kick in.
"He was truly a remarkable man, a wonderful rugby coach but also a wonderful man as well."
Former London Welsh, Wales and Lions forward John Taylor described Dawes as the "thinking man's leader."
"I think people don't realise quite what a pioneer he was," Taylor told BBC Radio Wales Sport.
"He literally changed the way rugby was played back in the late 1960s, early 1970s and it was a remarkable story.
"He was always a terrific thinker about the game. John was always planning ahead.
"A journalist once said he was a ventriloquist - he made the ball talk and it was very true.
"He was the best receiver, passer of the ball that I have ever seen and that still goes today."