The former London Welsh, Bridgend and Barbarians full-back was a pivotal part of Wales and The Lions' glories in the 1970s.

Williams captained Wales and his hometown club Bridgend and he also represented his country 55 times. 

Williams accumulated eight test caps during historic triumphant Lions tours to New Zealand in 1971 and South Africa in 1974.

A statement from the Williams family said: "JPR died peacefully today at the University Hospital of Wales surrounded by his loving wife and four children, after a short illness, bravely battling bacterial meningitis.

"The family request privacy at this difficult time."

Williams won three Five Nations Grand Slams- in 1971, 1976 and 1978. He retired from the international stage in 1981, but he continued to play rugby on occasion before he finally hung up the boots in 2003.

New Welsh Rugby Union (WRU) president Terry Cobner played with Williams in the 1976 and 1978 Grand Slam campaigns, as well as the 1977 Triple Crown season.

"The world of rugby has lost one of its greatest players of all time, a man who revolutionised full-back play," said Cobner.

"He was the defensive rock in every team in which he played, the counter-attacking inspiration and the man who feared nothing and never saw a lost cause. We all thought he was 'Mr Indestructible'.

"Although he played during the amateur era, he was thoroughly professional in his sporting outlook and always drove standards in training and on the field. With JPR in your side, there was always a chance of winning anything.

"Welsh rugby will remember him as one of our greatest players of all time - those 55 caps, three Grand Slams and six Triple Crowns prove that.

"He also played in all eight Tests in New Zealand and South Africa on arguably the two greatest tours undertaken by the Lions, in 1971 and 1974.

"It was his drop goal from near half-way that enabled the 1971 Lions to draw the fourth Test and win the series 2-1 against the mighty All Blacks - the only series victory by the Lions on New Zealand soil.

"A star in the making from his early school days at Bridgend Grammar, then at Millfield, he went on to thrill crowds at both London Welsh and Bridgend on the club scene. He was 'box office' wherever he went.

"This is a terrible loss for our game, but obviously an even worse loss for his wife Scilla and their children. The thoughts of the whole Welsh rugby family are with them at this difficult time."