O'Neill took the Villa job - but only because he knew Ellis was leaving
The day Doug Ellis handed over control of his beloved club to a new owner was one many Aston Villa fans doubted they would ever see.
The 82-year-old once commented that the only way he would leave Villa was in a box - and few doubted his conviction.
Ellis has battled prostate cancer and a triple-heart bypass to stay in charge but now he has vacated the chairman's office for American billionaire Randy Lerner.
It marks the end of an era for the Midlands club - and indeed for English football.
Ellis, who revelled in the soubriquet Deadly Doug, has owned Villa for almost 40 years.
He first took over in 1968 and, apart from a spell from 1979-82 when he was ousted from the board, has been chairman ever since.
Ironically, that three-year hiatus turned out to be the most successful in the club's history, with Villa winning the old First Division title and then the European Cup.
On the face of it, Ellis leaves Villa in an enviable position.
They have minimal debt, a 42,000 stadium and one of the most respected managers in British football in Martin O'Neill.
Villa fans protested against Ellis at a pre-season friendly against Wolves
Yet, in truth, Ellis is unlikely to be missed by the club's fans, players or management.
Jonathan Fear, spokesman for Villa Fans Combined and the Aston Villa Shareholders' Association, questioned the octogenarian at the club's Annual General Meeting.
"He is surrounded by yes men and no-one has the guts to tell him it is time to go," said Fear.
"It has been his life and he talks about Villa as his baby but Aston Villa was there before him and will be there long after him."
And before the departure of manager David O'Leary, some Villa players issued an anonymous statement questioning Ellis's ambition.
"We feel it should be a big club but if the chairman has got ambition he needs to start showing it," the statement read. "It has to come from the top."
Ellis appeared to pull off a major coup by persuading O'Neill to take over as Villa boss.
Yet this might not be quite as impressive an achievement as it seems because BBC Sport understands that O'Neill secured assurances from Ellis that he would relinquish control to Lerner before agreeing to take the job.
And although the club is only minimally in debt, its financial performance last season was almost as poor as its one on the pitch.
Villa lost £8.2m before tax, compared with a £3m profit the previous year, and income fell £51.6m to £49m, with attendances at Villa Park down 8.7%.
Ellis admitted: "It would be foolish to suggest that 2005-06 year was anything but a huge disappointment."
Yet what is beyond doubt is that English football is losing one of its most colourful and recognisable figures.
Doug's great strength is looking after the pennies - it takes up a large part of his working day
Former Villa manager
Ellis, who was brought up in Cheshire by his widowed mother, claims to have invented the package holiday and was a millionaire by the age of 40.
He took over at Villa when he was 44 and quickly became renowned for hiring and firing managers - 13 got the bullet during his chairmanship - and for his parsimony.
One of those managers, John Gregory, said: "Doug's great strength is looking after the pennies - it takes up a large part of his working day.
"He hates waste. If you stay in a hotel Doug cannot understand why you need a suite or a double. He says all bedrooms look exactly the same when you are asleep."
In fairness to Ellis, he saw the funny side of this reputation and even played up to it.
And he never hid away when there was controversy about his chairmanship.
But to say he will be missed by the Villa faithful is pushing things a bit too far.