1958: Born on May 5th, less than a mile from Highbury in Stoke Newington, the son of Irish parents.
1961: Moves to Dublin with family.
1973: Joins Arsenal as an apprentice after two week trial with Manchester United.
1974: Makes senior Arsenal debut at 17 in 3-3 First Division draw at Burnley, nearly a year before completing his apprenticeship and signing first full contract.
1976: Makes Republic of Ireland debut in 1-1 draw with England at Wembley.
1978: Makes first FA Cup final appearance in Arsenal side which loses 1-0 to Ipswich.
1979: Wins FA Cup winner's medal with Arsenal, beating Manchester United 3-2 after a dramatic last-minute winner by Alan Sunderland.
1981: Turns down a move to Manchester United and signs another four-year contract at Highbury.
1987: Wins English League Cup medal in 2-1 win over Liverpool.
1988: Recalled to the Republic of Ireland squad after two years in the international wilderness following a bust-up with manager Jack Charlton. Misses English League Cup final defeat by Luton with an Achilles injury.
1989: Wins first championship medal with Arsenal in dramatic win at Liverpool. Breaks club appearance record of 550 matches.
1990: Scores the winner in a penalty shoot-out against Romania to put the Republic of Ireland through to the quarter-finals of the World Cup in Italy.
1991: Wins second championship with the Gunners.
1992: Sent off for the first time in his career - in a reserve game at QPR.
1993: Captains Republic of Ireland in his 68th and final international against Wales but is carried off injured after just two minutes. Given a free transfer by Arsenal to take effect after completing his 20th year at the club. Wins English League Cup medal with Arsenal in 2-1 win over Sheffield Wednesday. Wins FA Cup winner's medal as extra-time substitute in replayed final against Sheffield Wednesday in his 721st competitive game for the Gunners. Moves to Leeds on a free transfer.
1995: Announces his retirement in October after failing to recover from an Achilles tendon injury after playing only 12 times for Leeds.
1996: Returns to Elland Road as assistant to new Leeds manager George Graham.
1998: Sent from the dug-out against Maritimo in UEFA Cup for abusing a match official. Takes temporary charge when Graham quits Leeds for Tottenham but claims he does not want the job on a permanent basis. Leeds chairman Peter Ridsdale admits that O'Leary is in pole position to become the new Leeds manager after Martin O'Neill decides to stay at Leicester.
