Sir Gareth Edwards has described John Dawes as one of Welsh rugby's "giant figures".
Former Wales and British and Irish Lions captain Dawes has died at the age of 80 following a period of ill health.
He famously led the Lions to their only series victory over New Zealand in 1971, making four Test appearances for the tourists and winning 22 caps for Wales.
As a 23-year-old centre, he made a try-scoring international debut against Ireland in Dublin in 1964 and his storied career included captaining and coaching his country to Grand Slam titles.
"John was a fantastic captain and a great coach," former Wales star Edwards – a 1971 Lions team-mate of Dawes – told the Welsh Rugby Union's official website.
"He is one of the giant figures of Welsh rugby of any era.
"He wasn't the fastest or most elusive player, but everyone around him benefited from his great skill and his distribution.
"You only have to look back at the 1971 Lions tour to see how Ireland's Mike Gibson shone playing outside him in the centre.
"He was part of the great try-scoring move for the Barbarians against New Zealand in 1973 (Edwards scored it) and I can still hear Cliff Morgan in commentary say, 'Dawes, great dummy'. That moment encapsulated John as he helped to set up a score that has never been forgotten.
"John was always calmness personified on the field amid the chaos of international rugby. People don't understand how valuable it is to have someone like that on your side, someone who can see the bigger picture and calm everyone down.
"He never went over the top about our success when he was coaching.
"He would calmly tell us when we gathered for the first time in a season that, while we weren't a good team at that moment, by the end of the season we would be a great side."
In a statement, Dawes' former club Newbridge said: "We are unfortunately having to report some very sad news. 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 within the game of rugby union.
"The heartfelt condolences of everyone here at Newbridge RFC go out to John's family at this very sad time."
Dawes, who played for London Welsh as well as Newbridge, was a central figure in Wales' glory years in the 1970s.
His most successful year in the Test arena was also his final one as he announced his international retirement in 1971 having won the Grand Slam and been at the helm for a 2-1 series victory over the All Blacks.
Two years later he enjoyed more success against New Zealand as he led the Barbarians in their famous 23-11 win at Cardiff Arms Park.
Dawes became Wales coach in 1974 and he masterminded Grand Slam triumphs in 1976 and 1978.
The Welsh Rugby Union tweeted: "It is with great sadness that we learnt today of the passing of Wales, @lionsofficial, @newbridgerfc, @LondonWelshRFC and @Barbarian_FC legend John Dawes."
A tweet from the Lions' account read: "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."
London Welsh saluted Dawes in a statement on their official website.
"It is with great sadness, but also much remembrance and celebration of a truly great life, that we confirm the death of former London Welsh player and coach, Welsh Rugby Union player and coach, British and Irish Lion, Barbarian, London Welsh honorary life member and club president: Sydney John Dawes OBE," the club said.
"Our very best wishes and thoughts go out to all of John's family, and particularly former player Mike Dawes (John's son) and current squad member Rhodri Dawes (grandson).
"This is a seismic loss to the London Welsh family, as well as the entire rugby community across the world.
"This evening, we remember one of the true greats of all time and one of our own."