Martin O'Neill has agreed to become Celtic's permanent manager.
The 74-year-old has given the green light to sign an initial one-year deal at Parkhead.
It follows talks with the club's major shareholder, Dermot Desmond, who had also held conversations with former player Robbie Keane - .
O'Neill returned to the club twice last season and guided them to a domestic double, including a Scottish Premiership title triumph on the final day of the season.
After lifting the Scottish Cup at Hampden Park last month, he felt the Hoops could be "looking at somebody younger" as they searched for a new boss.
However, O'Neill will remain at the club and is expected to be joined by his current backroom team of assistant Shaun Maloney, plus coaches Mark Fotheringham and Gavin Strachan.
Following the shock resignation of Brendan Rodgers last October, there was even more surprise as O'Neill was given the call to take over on an interim basis - 20 years after his previous spell at the club.
During that period, he won every league game to turn an eight-point deficit to Hearts into a situation where Celtic were level on points with a game in hand.
O'Neill also led Celtic to the League Cup final after beating Rangers, plus boosted their Europa League hopes.
He then made way for Wilfried Nancy. However, the Frenchman lasted just 33 days into his two-and-a-half-year deal, and O'Neill returned again - this time until the end of the season.
At that stage, Celtic had slipped six points behind Hearts and seen Rangers draw level on points, with the club having also lost the League Cup final.
However, O'Neill helped the Hoops recover on and off the park. Off it, he guided the club through the January transfer window, plus worked to quell unrest between the fans and board.
On it, he secured a spot at Hampden in the Scottish Cup, plus cut that gap to Hearts in the league before pipping them to the title after a final-day decider.
Then came that Scottish Cup final as he overcame his former captain Neil Lennon's Dunfermline at the national stadium.
More than two decades on from his last spell in Glasgow, O'Neill added two more trophies to the seven he had won at the club from 2000-2005. Now, he will hope more follow.
A number of Celtic supporters clubs had put their names to a statement opposing the potential appointment of Robbie Keane as manager, due to his previous role with Maccabi Tel Aviv.
Keane was among the favourites to take charge following talks with principal shareholder Dermot Desmond.
The Republic of Ireland's record goalscorer enjoyed a prolific loan spell at Celtic Park in 2010 and has won league titles in Israel and Hungary as a manager.
However, his decision to stay in Israel after the conflict in Gaza began sparked criticism in Ireland and had turned a section of the Celtic support against him.
Graffiti and banners opposing the prospect of Keane becoming manager have appeared outside Celtic Park in recent days and a statement emerged online from a group calling itself Celtic Fans for the Liberation of Palestine.
Former Celtic midfielder Stiliyan Petrov to Your Site News:
"I'm actually surprised - I thought they would offer Martin O'Neill a different role, a more relaxed one. But with his management skills and record for major honours, he has justified his appointment. I hope and wish him all the best for the next season. Martin O'Neill is Martin O'Neill.
"He'll feel about 102 by the time that year flies past! But with a one-year deal, they just want to stabilise the club. The last couple of months, he has shown why he's been such a great character. But here's a question: if they win again next year, what's going to happen?
"I've followed Robbie Keane's managerial career and he's done really well. But when you compare him with O'Neill, you have that maturity with O'Neill, who agreed to continue with this team.
"There was no doubt about it: he was always going to be the first choice if he agreed to it and showed the same energy and determination to work for this great club.
"Complicity, motivation, man management, this is everything that he's done in his career. He's a great motivator, he demands very high performances from every single player. He keeps everything simple. He trusts his staff. When you have that, you have a manager with a pedigree where only one thing can be achieved: the best.
"If O'Neill has agreed to become Celtic manager, he knows the challenges. He knows he needs to add quality, strong characters and big players who can win games.
"I hope Celtic have learned their lessons, because Rangers will be stronger next season, Hearts will try to push again. Celtic need to have a strong team in Europe and domestically. Last season, they got away with it. Next season will be a big challenge."
In a season of twists and turns, people thought Hearts might become the first non-Old Firm club to become top-flight champions since 1960. By the end, it was Celtic who once again rewrote the record books.
Since 1930, Rangers had more league titles to their name, but in recent years that gap narrowed, before Celtic drew level on 55 last season. Now, they lead that race on their own with 56.
It has been a generation of domination, with the Hoops winning the league 20 times compared to Rangers' six since 2000.
The bragging rights well and truly belong to Celtic.
