Last Updated: 30/03/13 9:56pm
Sunderland have sacked manager Martin O'Neill following Saturday's defeat against Manchester United and it brings to an end a near 16-month spell in charge at the Stadium of Light.
O'Neill had replaced Steve Bruce on Wearside and took over on the back of an impressive managerial CV.
Here, Sky Sports takes a look back at both O'Neill's playing and managerial career following his departure from Sunderland.
1952: Born Kilrea in Northern Ireland, March 1.
1971: Makes international debut as a substitute against the USSR. Joins Nottingham Forest from Distillery in October.
1978: Member of Forest's league and League Cup double-winning side.
1979: Wins a second League Cup winner's medal as Forest retain trophy with 3-2 victory over Southampton.
1980: Wins European Cup as Forest beat German champions Hamburg 1-0 in Madrid.
1981: After 285 league appearances for Forest, with 48 goals, joins Norwich in February for the first of two spells as a player at Carrow Road. After 11 league appearances and one goal transfers to Manchester City.
1982: Returns to Norwich in January after playing just 13 league games for City. Makes 55 league appearances, scoring 11 goals.
1983: Returns to Nottingham in August, joining Notts County, making 64 league appearances with five goals.
1984: Wins last of 64 international caps in 2-1 win over Finland.
1990: Appointed manager of non-league Wycombe after spells with Stamford and Shepshed Charterhouse.
1991: Guides Wycombe to victory in the FA Trophy.
1993: Wycombe win GM Vauxhall Conference, securing promotion to the Football League. Clinches another FA Trophy success.
1994: Leads Wycombe to promotion from Division Three at the first attempt.
1995: Becomes manager of Norwich in June.
Resigns on December 17 after a series of clashes with chairman Robert Chase over money for team building. Appointed manager of Leicester on December 21.
1996: Leicester beat Crystal Palace 2-1 at Wembley in the First Division play-off final, winning promotion back to the Premiership at first attempt.
1997: Wins Coca-Cola Cup final, beating Middlesbrough in a replay at Hillsborough.
Guides Leicester to ninth-place finish in Premiership.
1998: Finishes 10th in Premiership with the Foxes but O'Neill frequently voices concern over lack of funds.
1999: Leads Leicester to Worthington Cup final, where they are beaten by Tottenham, and to 10th place in the Premiership.
2000: February - Leads Leicester to another Worthington Cup win as they defeat Tranmere 2-1 at Wembley.
June 1 - Becomes Celtic manager.
2001: March - Wins first trophy in Scotland with a 3-0 CIS Insurance Cup final victory over Kilmarnock.
April - Celtic win Scottish Premier League title.
May - Beat Hibernian 3-0 to win Scottish Cup final and complete a domestic treble.
2002: April - Celtic secure the Scottish Premier League title again with a 5-1 win over Livingston.
May - Celtic lose 3-2 in extra-time to Porto - managed by Jose Mourinho - in UEFA Cup final in Seville.
2003: Celtic lose SPL title to Rangers on thrilling final day.
2004: April 18 - Regains SPL title with 1-0 win at Kilmarnock with six games to spare.
May 22 - Earns second double in four years with 3-1 win over Dunfermline in Scottish Cup final.
July - Delays arrival in America for pre-season trip to care for sick wife, Geraldine.
2005: May 22 - Two late goals see Celtic lose 2-1 at Motherwell - and O'Neill's hopes of a fourth title in five years disappear as Rangers win 1-0 at Hibernian.
May 25 - Club announce O'Neill will step down after Scottish Cup final.
May 28 - Ends career at Celtic with 1-0 win over Dundee United in Scottish Cup final at Hampden Park.
2006: July 4 - Confirmed as manager of Aston Villa.
2007: May - Villa finish 11th in Premier League.
Following departure of Steve McClaren rules himself out of England job.
2008: May - Villa finish sixth in Premier League.
2009: May 2 - Villa finish sixth again, a run of nine games without a win costing them Champions League place.
August 27 - Fails to take Villa to the group stages of the Europa League following a 2-2 aggregate draw with Rapid Vienna. Rapid progress on away goals.
2010: February 28 - Reaches his first final with Villa - but they lose the Carling Cup 2-1 to Manchester United.
April 10 - Villa lose 3-0 to Chelsea in the FA Cup semi-final.
May - Villa finish sixth in the Premier League for a third successive year.
August 9 - Villa announce O'Neill has resigned as manager with immediate effect.
2011: November 18 - Rules himself out of the Northern Ireland manager's job, but agrees to help find the new man.
December 3 - Appointed manager of Sunderland, the team he supported as a boy, on a three-year contract.
Leads Sunderland away from trouble by guiding them to a 13th place finish in the Premier League.
2013: March 30 - Leaves Sunderland after a 1-0 home defeat against Manchester United leaves the team one point above the relegation zone.