Jony Ive has shocked Silicon Valley by walking away from the iPhone maker after 25 years.
His departure has been hailed as the "end of an era" and a move that raises questions about Apple's future.
"My Apple world feels a bit ripped apart this morning," one writer for Apple blog The Loop said. "This feels like a friendly but still quite painful divorce."
However, Sir Jony's exit has been a long time coming. In 2015, the mild-mannered designer told The New Yorker that he was "deeply, deeply tired". Not long after, Apple announced that Sir Jony had stepped back from day-to-day management of the design team to allow him to take a break.
In the years since, the 52-year-old is believed to have gradually shed even more responsibility.
"He's been at Apple over 25 years, and it's a really taxing job," an insider told Bloomberg. "It's been an extremely tense 25 years for him at Apple and there's a time for everyone to slow down."
Sir Jony has never been one to follow the rules or subscribe to the unquestioning enthusiasm shown by some Silicon Valley bosses.
He famously installed a speaker set-up in Apple's design office so that brainstorming meetings for the company's newest gadgets could be accompanied by Sir Jony's favourite work soundtrack: loud techno music.
Ive was head of Apple's design studio in 1996, but it was the candy-colored iMacs released in 1998 that helped Apple raise its fortune.
Two million iMacs were sold in 1998, giving Apple its first profitable year since 1995.
He came to prominence in 1998 with the candy-colored iMacs, which were kind of fun and colorful, and all things that computing had not been for the prior 30-odd years. Computing had been kind of dull and gray and serious.
In recent years, the design star has been spending more time in London after purchasing a private jet from the widow of late Apple founder Steve Jobs.
Cook is likely to have realised that Sir Jony was getting restless. In 2013, he was put in charge of the design of Apple's software - something many see as a mistake.
With iOS 7, Ive upended the look and feel of the iPhone's apps.
His radical, colourful design was criticised as "confusing" and "ugly".
Even John Gruber, the Apple writer who is friendly with the company's executives, wrote that "under [Sir Jony's] control, we've seen the software design decline and the hardware go wonky". Ive's departure may even be good news, Gruber suggested.
Shift to services
Apple's shift to focus on services over hardware left fewer avenues for Ive to unleash his design talent.
He began working on side projects, such as a Christmas tree without any decorations for Claridge's, a blank magazine cover for Wallpaper magazine, and a minimalist ring carved from a single diamond.
The project that took up most of his time, however, was the design of Apple's $5bn (pounds 3.9bn) new office campus.
The building, which resembles a hollowed-out spaceship, has a park in the middle, and Sir Jony's obsessive design perfectionism throughout the building.
The building officially opened this year and features custom-built door handles and glass roofs designed to stop water pooling on them. Clearly, it was a labour of love for Sir Jony.
There was a sign that Sir Jony may have recommitted to Apple in 2017 when he returned to his managerial role, but the excitement was short-lived.
With Sir Jony's departure now official, many are questioning what it will mean for Apple. Sir Jony has set up his own company, LoveFrom, which launches fully in 2020 with Apple among its first clients.
'I will still be very involved' [with Apple]
"While I will not be an [Apple] employee, I will still be very involved — I hope for many, many years to come," he told the Financial Times. "This just seems like a natural and gentle time to make this change."
Nehal Chokshi, an analyst with Maxim Group, said that despite Ive's key role in Apple history, his departure will not hurt the iPhone maker.
"I would view it as Jony Ive looking to get paid market rates for his design expertise from Apple, with the right to allow other companies — not competitors to Apple — to leverage that expertise," he said.
Sir Jony was the totemic figure who represented Apple's rebirth following the return of Jobs in 1997.
Under Jobs and Sir Jony's direction, the company released the iMac, iPod and iPhone, creating a trillion-dollar technology icon.
But times have changed for Apple, and the company is looking beyond Sir Jony's beautifully designed smartphones. It's a new era for Apple, and seemingly the perfect time for Ive to finally make his exit.
The Telegraph Group Ltd., London, 2019