The year was 1960 and they were still young and unknown. It would be a few years yet until the screams of Beatlemania echoed around the globe...
Yet young German photograph Astrid Kirchherr was in the right place at the right time; not only witnessing The Beatles early garage rock performances in Hamburg, Germany, but also becoming engaged to the group's bassist, Stuart Sutcliffe.
Sutcliffe would die just two years' later, and the pair's love affair has since become the stuff of legend - including a biopic with 1990s film Backbeat. Subsequent generations of collectors remain captivated by the Fab Four's (or then Fab Five's) early pre-fame years.
Kirchherr was introduced to the group after her then-boyfriend, Klaus Voormann - later the artist behind The Beatles' Revolver LP sleeve and bassist on John Lennon's solo records - wandered into a Beatles gig following an argument with her.
Astrid soon wanted to get as close as possible to the group, and naturally ended up photographing them during their time in Hamburg.
Eventually romance blossomed between Astrid and Stuart, prompting the bassist to leave The Beatles to study at Hamburg College of Art in 1961 where he became regarded as one of the school's best students.
Astrid's 'half shadow' photography would influence later photographers' images of the group, and her works are today essential pieces of rock 'n' roll history.
Virtually every book written about The Beatles includes Kirchherr's vital works.
Fast-forward half and century, and Kirchherr's images are now appearing for sale on the private markets - along with their negatives and even copyright - in Guernsey's massive September 24-25 online auction, this weekend.
In the words of Guernsey's President Alan Ettinger, in these images you see The Beatles "in their raw, rugged best" - before Brian Epstein tidied up their image to become the 'mop tops' that would eventually conquer the world.
Because the winning bidder will also own the images' copyright, it will give them unprecedented access and control over these singular documents of The Beatles' early years.
Other lots in the sale focus more specifically on the relationship between Kirchherr and Sutcliffe, including a letter written to Sutcliffe's mother by Astrid just two months are his death from a brain aneurysm.
"My darling is two months away from me... it seems like he is away for 50 years," reads Astrid's letter.
Elsewhere in the sale, another lot gives invaluable insight into the artistic development of Sutcliffe himself: an essay on the artist Hans Holbein written during his time at art college.
On April 1962, Kirchherr would meet the rest of The Beatles at Hamburg airport to tell them that Sutcliffe had died. Later, in the words of Yoko Ono, John Lennon would often mention Sutcliffe as being "[My] alter ego ... a spirit in his world ... a guiding force."
Astrid Kirchherr's letter written two months after Stuart Sutcliffe's death
As far as The Beatles are concerned the rest is, of course, history - yet collectors now have a chance to acquire invaluable pieces of the foundations of this history at Guernsey's sale.
Watch this space for more news on the auction.