Roy Keane has signed a three-year contract to become the manager of Championship side Sunderland.
Keane has taken his first managerial role
Keane, who will be unveiled at 1300 BST on Tuesday, watched from the stands as Sunderland beat West Brom to record their first win of the season.
"This represents a major coup for our football club," Sunderland chairman Niall Quinn told the club website.
Tony Loughlan leaves his role with Leicester's academy to join Keane's backroom staff as head coach.
Quinn added: "The fact that one of the most influential figures (Keane) in world football is willing to come here should make all the Sunderland fans very happy.
They showed they wanted to play for the manager, they were playing for their futures
Sunderland chairman Niall Quinn
"Roy Keane's standards of professionalism are legendary and his desire and determination to succeed are precisely what this club requires.
"Let's all support and enjoy one of football's true greats as he embarks on what we all hope will be a fantastic new chapter in Sunderland Football Club's rich and proud history."
Keane signed autographs as he took his place in the stands at the Stadium of Light for Sunderland's game against the Baggies.
"He brought a buzz to the place. They showed they wanted to play for the manager, they were playing for their futures," Quinn said of Keane after the victory.
Keane, 35, is expected to be formally unveiled at a news conference on Tuesday having been introduced to the Sunderland squad on Sunday.
Keane (left) was sat with Loughlan at the Stadium of Light
"When Roy met players, you could almost see them standing an inch or two taller thinking 'we are going to be working with that man, that is incredible'," added Quinn.
"Possibly, the players are a bit scared. I hope they are, not in the sense they will underperform but that they will give their all when they go training.
"This is a very demanding place but standards are going to have to be lifted.
"You only have to spend a short amount of time in Roy's company to realise just how impressive he is."
Loughlan, who was sat next to Keane during the game against West Brom, was responsible for the coaching and development of eight to 13 year olds at Leicester City's academy.
He is a former Foxes youth player and had spells at Nottingham Forest and Lincoln City.
Sunderland have had a difficult start to their Championship season following their relegation from the Premiership.
The Wearside club lost their four opening league fixtures as well as being knocked out of the Carling Cup after a 2-0 loss to lowly Bury.
It will be former Nottingham Forest, Manchester United and Celtic midfielder Keane's first steps into management, after injury ended his glittering playing career in June 2006.
Keane replaces his former Republic of Ireland team-mate Quinn, who occupied the role while a permanent choice was sought.