Highs
1990 - Snapped up by Clough
Gets his big break in professional football when Nottingham Forest boss Brian Clough signs him from League of Ireland club Cobh Ramblers for £10,000. Does not take long to make an impact, making his debut for Forest at Liverpool and being named Barclays Young Eagle of the Month for December.
1991 - International debut
Impresses Jack Charlton enough to hand him his international bow for the Republic of Ireland in 1-1 draw with Chile in Dublin.
1993 - The big-money move
After competition from a host of clubs he joins Manchester United for a then British transfer record fee of £3.75million after 154 matches and 33 goals for Forest.
1994 - Instant success
Marks first season with United by helping club complete their first League and FA Cup double.
1994 - American adventure
Helps the Republic reach the second round of the World Cup in the United States, figuring in all four matches.
1996 - Double Double
An inspirational presence as United clinch historic second double with 1-0 FA Cup final win over Liverpool.
1997 - The natural successor
Eric Cantona's retirement from professional football opens up a vacancy for the United captaincy. Sir Alex Ferguson has no hesitation in naming Keane as the new man.
1999 - The match winner
Scores the goal that earns United a 1-0 Toyota Cup victory over Palmeiras of Brazil. United are the first British club to lift the Inter-Continental Cup.
2000 - Talents recognised
Named PFA and Football Writers' Association player of the year before lifting Premier League title for the sixth time in eight years.
2003 - Champions
Lifts the Premier League trophy at Goodison Park as United hold off Arsenal for the title.
2004 - Return to the fold
Makes first appearance for Ireland since Mick McCarthy bust-up in friendly with Romania.
2005 - Goalscoring landmark
Scores his 50th goal for United in 2-0 Premier League win over Birmingham.
2005 - Signs for Celtic
Joins club he always hoped to play for, and goes on to help Celtic win Scottish Premier League title in 2006.
2006 - Moves into management
Appointed boss at Sunderland early in 2006-07 season.
2007 - Wins promotion
Steers Sunderland to Coca-Cola
Championship
title having taken over the side in the relegation zone.
2009 - Tractor Roy
Returns to management at Ipswich.
Lows
1991 - Run-in with big Jack
Even as a teenager, Keane was not afraid to stand up to authority. Following a friendly against the United States, the Republic of Ireland team were allowed a night out. The next morning, with departure set for 7.30am, the team were kept waiting until 8am by Keane, invoking the wrath of manager Jack Charlton.
1999 - "Annoyed" by contract offer
Keane admitted his unhappiness with the first new contract offer he received from Manchester United. He said: "I was a bit annoyed with the first offer put to me. Deep down they must have known it wasn't something I could sign. Our dealings have to be realistic. I am not naive enough to settle for anything less than a reasonable valuation of my worth."
2000 - Furious letter to fans
Keane brands United's decision to blame his £52,000-a-week wages for the hike in season ticket prices as "a stupid mistake". The club sent a letter to fans claiming that one of the reasons for the ticket increases was Keane's wage rise.
2000 - The prawn sandwich affair
Keane hits out at sections of Manchester United's support following what he felt was a poor atmosphere in the club's Champions League clash with Dynamo Kiev.
2001 - When the "red mist" descends
Keane admitted there were "no excuses" for his continuing lack of discipline after being shown a red card for the 10th time in his career.
2001 - Alf-Inge Haaland
Having suffered a serious knee injury in a clash with Haaland earlier in his career, Keane got his revenge in a Manchester derby. A crude stamp on the Norwegian's knee earned a red card and left Haaland badly injured. In his autobiography Keane admitted: "I waited until five minutes before the end, I hit him hard."
2002 - Thrown out of World Cup
An exasperated Keane announces he will quit international football after the World Cup having expressed his dissatisfaction with the Republic's preparations. When clear-the-air talks with McCarthy descend into a "slanging match", the Republic boss promptly sends his best player home.
2003 - International retirement
Despite the efforts of new Ireland manager Brian Kerr to tempt him back into the Republic's set-up, Keane announces his intention to retire from international football.
2004 - Champions League dismissal
Sent off as United lose in Porto in a Champions League last-16 clash. Misses the second leg at Old Trafford as the Red Devils crash out of Europe at the hands of Jose Mourinho's eventual champions.
2005 - Keane angers Saints fans
Invokes the wrath of Southampton fans by mocking their relegation plight before being ushered off the pitch after a 2-1 win at St Mary's, a result that contributed to the Saints drop from the Premiership.
2005 - Denied record-making opportunity
A United victory in the FA Cup final would have granted Keane a record-equalling fifth winners' medal. As it is, Arsenal emerge triumphant on penalties in a game that United dominated.
2005 - Announces exit plans
Keane reveals he expects to leave United in summer 2006, ending a 13-year Old Trafford career. He stresses he would play for no other English club.
2005 - International exit (again)
Two days after the Republic of Ireland fail to qualify for the World Cup in Germany Keane announces he is to quit international football for a second time.
2006 - Retirement
Announces retirement following medical advice.
2008 - Exits Sunderland
Leaves his first managerial post after crisis talks on Wearside.