The 37 shots of the Fab Four on a U.K. tour with Helen Shapiro in 1963 were unearthed by photographer/journalist Paul Berriff at his home in north England.
He took the pictures after the band gave him unlimited access on tour when he was a teenage snapper - just months before Beatlemania gripped the world, leading to a security clampdown and a new set of rules which limited the photographers who were allowed to work with the band.
Berriff had stored the negatives at his home, along with hundreds of other images of British musicians in the 1960s.
The Beatles photos, which chronicle the band members rehearsing onstage, smoking in their dressing room, and relaxing with drinks and snacks backstage, will go on display at London's Menier Gallery on Wednesday.
Berriff says, "I started to root around in my attic and I found this box of about 800 negs (negatives), and in it were shots of these old pop groups in '63. I was absolutely knocked out when I saw the quality and realized I should do something with them."
And Berriff has fond memories of the time he spent around the Fab Four - he even made friends with Paul McCartney.
He adds, "Paul got to know me quite well, and every time they came up to Yorkshire or Manchester they would say 'Hi Paul, how's things going?'"