From his arrival at Nottingham Forest in 1990 Keane's career has never been dull.
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 Ireland 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, which Sir Alex Ferguson has no hesitancy over naming Keane as the new man.
1999 - THE MATCHWINNER:In what is widely recognised as his finest performance, he scores United's opening goal and leads a stunning comeback against Juventus in Turin. After getting booked early on, he knows he will miss the Champions League final but still plays his heart out to ensure United come from 2-0 down to win 3-2.
1999 - THE MATCHWINNER II :Scores the goal which 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 Premiership title for the sixth time in eight years.
2003 - PREMIERSHIP CHAMPIONS:Lifts the Premiership 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 Premiership win over Birmingham.
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 - KEANE "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 - KEANE FURIOUS WITH 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.
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.
2002 - SENT HOME FROM 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.
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."
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 Barclays Premiership.
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.
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.
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.
UNITED EXIT:Leaves Manchester United by mutual consent with immediate effect.