The man responsible for the Beatles' business affairs has quit after more than 40 years with the band.
The Beatles set up record label Apple Corps in 1968
Neil Aspinall, 64, started out as the group's road manager and used to drive them to gigs in his van.
As the head of the band's Apple Corps business, he oversaw releases like the Anthology series and was sometimes referred to as the "fifth Beatle".
He will be replaced by Jeff Jones, a US music executive who specialises in repackaging classic albums.
Mr Jones, who will relocate to London, said the job was "a dream come true".
"This is astonishing news," said former Apple press officer Geoff Baker told the Associated Press news agency.
"Neil was the architect of all the Beatles' success over the past 15 or 20 years. I can't see how the Beatles legacy will be looked after as well without him.
Aspinall went to school with Sir Paul McCartney
"I'm amazed that Paul and Ringo are letting this happen."
In a statement, Apple Corps said Mr Aspinall "played an indispensable role" in the Beatles' story.
"He was there since the inception of the band in Liverpool and has meant so much to the Beatles family for all these years, and still does."
Mr Aspinall was a childhood friend of Paul McCartney and George Harrison, and later became personal assistant to the band.
When the group set up their Apple record label in 1968, he was put in charge - and managed to survive the company's chaotic beginnings, when profligate spending almost drove the company to bankruptcy.
Notoriously media-shy, Mr Aspinall was nonetheless a hard-nosed businessman who fought hard to protect the Beatles' music, image and copyright.
He was behind the band's decision not to release their music on compact disc for several years, holding out for a higher royalty rate before launching the iconic Sergeant Pepper album in 1987 amid a worldwide publicity blitz.
The Beatles have yet to make their music available online
Mr Aspinall was also the main reason why Beatles tracks are not heard on multi-artist compilation albums, because he said they cheapened the band's image.
He was behind several legal cases brought on the band's behalf - including the recently settled dispute with Apple Computers over the Apple name and logo.
But one of his main roles was to negotiate and keep the peace among his four bosses - Paul McCartney and Ringo Starr, John Lennon's widow Yoko Ono and George Harrison's widow Olivia Harrison.
However, he was not the only associate of the band to be called the "fifth Beatle" - producer Sir George Martin and manager Brian Epstein have also been rewarded with the title.