Former Celtic captain Billy McNeill has died at the age of 79, his family has announced.
McNeill, who played for Celtic his whole career, was captain of the famous 'Lisbon Lions' side that was the first British side to lift the European Cup in 1967 and he also went on to manage the club.
A statement from his children on the Celtic website read: "It is with great sadness that we announce the death of our father Billy McNeill.
"He passed away late last night (Monday, April 22) surrounded by his family and loved ones.
"He suffered from dementia for a number of years and fought bravely to the end, showing the strength and fortitude he always has done throughout his life."
The football world reacted with a flood of tributes to the legendary figure.
Sir Alex Ferguson, who played directly against McNeill in Old Firm derbies and succeeded his former opponent as Aberdeen manager, said: "He was a giant in Scottish football, a man with an incredible presence and I'll always cherish the fact that we entered professional football at the same time.
"We played against each other on many occasions and, as anyone who played against him will testify, he was the fairest of players.
"He was also a truly good man and will be a loss to everyone who knew him. Farewell Cesar."
Football pundit and former Celtic striker Chris Sutton tweeted: "Such heartbreaking news.
"Billy McNeill was an inspirational leader, a legend and a lion. Thoughts go out to his family and the Celtic family."
Athletic Bilbao, who recently awarded McNeill's family with a "one club man" award for his playing career with Celtic, tweeted: "Athletic Club regrets the passing of @CelticFC legend Billy McNeill and joins the pain of family, friends and the entire emblematic club."
In a statement posted on the club's website, Celtic manager Neil Lennon said: "As a Celtic supporter, to get the chance to play for the club, captain the team and finally to become manager is something that dreams are made of.
"The fact that I've achieved all three is something that I really appreciate, and the fact that I'm following in the footsteps of a legend like Billy McNeill makes me truly lucky."
Former Celtic striker Frank McGarvey, who McNeill signed from Liverpool in 1980, said: "It is a very very sad day.
"He was loved by all the players and you don't hear that about all managers."
McNeill was the captain of Jock Stein's all-conquering Celtic side of the late 1960s and early 70s, winning nine league titles in a row, seven Scottish Cups and six League Cups.
McNeill joined Celtic in 1957 from junior side Blantyre Victoria and holds the club record for most appearances with 822 over 18 seasons. The defender also won 29 caps for Scotland.
He had two spells as Celtic manager spanning nearly 10 years in total and won at total of 31 trophies with the club as player and manager.
He retained a strong association with Celtic throughout the rest of his life, becoming an ambassador in 2009.
But he will forever be identified with Celtic's 2-1 triumph over Inter Milan in Portugal.