But fate stepped in and dealt the affable London Welsh and Swansea No 8 and bitter blow. Playing for Swansea in the Welsh Cup semi-final against Pontypool at Cardiff Arms Park he suffered a brain haemorrhage.
He died three times in the ambulance on the way to hospital, but was successfully revived. He was only 29 and was at the peak of his powers.
It took him many months to recover from his operation and his retirement took its toll. "From competing against New Zealand one minute to not being able to beat my one-year-old son at tiddlywinks was a hard battle to come to terms with," he said.
The fact he lived for a further 36 years after his illness said as much about his strength of character and fighting spirit as his uncompromising, winning style on the field.
Davies rocketed from the third XV at London Welsh to the Wales side for the opening game of the 1969 Five Nations championship within a matter of four months and then played 38 games in a row for his country. He became one of the first names down on the team sheet.
He won three Triple crowns, two Grand Slams and two Lions Test series. In New Zealand he became known and respected as one of the biggest thorns in their side. He was inducted into the IRB Hall of Fame in 2001 and was regularly voted Wales greatest ever No 8 and captain.
"I remember being in a selection meeting at London Welsh shortly after he had joined the club when it was suggested Merve should be elevated from the Dragons to the Druids. The third team captain, Glan Richards, told us he had 'this big lad, long and thin, who will win you some line-out ball, but isn't very good'," said John Dawes, who captained him at club, international and Lions levels.
"By October he had made his debut in the first team and in January he was in the Welsh side. He played 38 consecutive games for Wales, became an icon and is up there with the greatest players of all-time.
"He loved playing and you could totally rely on him - he was totally uncompromising. As a captain he led by example, was tremendously courageous and never opted out of anything.
"Had it not been for his unfortunate brain haemorrhage in 1976, he would have led the 1977 British & Irish Lions to New Zealand and I think we might have won the series. His would be one of the first names down on the team sheet for any greatest ever Wales and Lions XVs."
Gareth Edwards had the distinction of playing with Davies in all 38 games he played for Wales and his eight Lions tests. He described him a "a great player and a great team mate."
The British & Irish Lions offer their sincere condolences to the family.