To date, The Beatles are the most successful music artists in the history of the world and remain as popular as ever over 60 years since they formed. Last night, Sir Paul McCartney was a talking head on BBC One’s The Queen: 70 Glorious Years, looking back at the band’s impact during the monarch’s reign, including the big changes in youth culture during the 1960s. And at one point the 79-year-old made a huge claim during the programme concerning the Fab Four’s formation.

McCartney was reflecting on the UK’s National Service, which had come into force in January 1949.

It meant that all physically fit young men aged between 17-21 had to serve in one of the British armed forces for 18 months.

The peacetime call-up after World War II ended in 1960, and The Beatles’ legend reckons this was extraordinarily significant for his band.

He said: “We were the generation that grew up fully expecting to go in the National Service. And then the second we qualified, it was as if God came down and sort of parted the waters and said, ‘You don’t have to go in.’ It was like, ‘Oh thanks!’ And I say, without that, there wouldn’t have been The Beatles. [The Sixties youth culture] was such an awakening. You were part of a cultural revolution. You wouldn’t call it that, it was just having fun.”

According to McCartney’s 1997 authorised biography, Many Years From Now, the star said: “I always thought [his time in the military] ruined Elvis. We liked Elvis’ freedom as a trucker, as a guy in jeans and swivelin’ hips. But [we] didn’t like him with the short haircut in the army calling everyone ‘sir.’

Commenting on Elvis’ post-army songs like Hard-Headed Woman, The Beatles legend said: “There’s a dreadful great big trombone right in the middle of it, and we thought, ‘What in hell has happened?’ It just seemed he’d gone establishment, and his records after that weren’t so good.”

Lennon agreed with his bandmate, telling BBC Radio 1 just two days before his death in 1980: “When Elvis died, people were harassing me in Tokyo for a comment.Well I’ll give it yer now, he died when he went in the army. That’s when they killed him. The rest of it was just a living death. But [it wasn’t like] going to a Zen monastery and going to India to meditate. Or going to Scotland and growing melons or something, whatever they’re doing up there in that place.”