The eventful life of the former Celtic manager:
1971 Born Lurgan, Northern Ireland, June 25.
1987 Starts career with Manchester City, making just one appearance after back problems.
1990 Joins Crewe Alexandra on free transfer.
1994 Wins first Northern Ireland cap.
1996 Joins Leicester for £750,000. Club is promoted to Premier League.
1997 Wins League Cup beating Middlesbrough.
2000 February: Wins second League Cup after Leicester beat Tranmere.
December 8: Completes £5.75m switch to Celtic.
2001 March 1: Reveals he is considering international retirement after being booed by Northern Ireland fans in defeat to Norway.
May 26: Celtic complete a domestic treble.
2002 August: Pulls out of Northern Ireland side before match v Cyprus after death threat. With 40 caps, retires from international football.
2003 May: Attacked in Glasgow's West End after being abused while driving. Plays in Uefa Cup Final extra-time defeat by Porto.
2004 May: Celtic win double with Scottish Cup final win over Dunfermline.
2005 June: Made Celtic captain by Gordon Strachan.
2007 Plays last Celtic match in a 1-0 Scottish Cup final win over Dunfermline.
Joins Nottingham Forest.
2008 April: Takes up coaching role with Celtic.
September: Requires hospital treatment after attack in Glasgow's West End after an Old Firm game. 2010 March: Takes over as head coach on interim basis after Tony Mowbray is sacked.
April: Celtic suffer shock defeat to Ross County in the last four of Scottish Cup. June 9: Confirmed as Celtic manager.
2011 January 5: Package meant for Lennon with bullets inside is intercepted at a sorting office in Country Antrim.
March 4: Celtic confirm he has been put under 24-hour security surveillance after suspicious package is intercepted at a sorting office in Ayrshire.
March 10: Lennon is handed a four-match ban for clashing with Rangers assistant Ally McCoist during Scottish Cup win.
March 20: Celtic lose League Cup final 2-1 to Rangers.
May 11: Attacked in Tynecastle technical area by a Hearts fan.
May 21: Celtic defeat Motherwell 3-0 in the Scottish Cup Final days after losing out to Rangers in the title race.
2012 April: Celtic clinch SPL title but lose to Hearts in Scottish Cup semi-finals. Two Ayrshire men are jailed for five years each for sending parcel bombs to Lennon and others.
November 7: Celtic beat Barcelona in Champions League group stages.
2013 March: Celtic suffer a 5-0 aggregate defeat by Juventus in Champions League last 16.
April 21: Celtic clinch title.
May 26: First double as manager after Scottish Cup victory over Hibs.
2014 February: Missiles thrown as Lennon watches Aberdeen's League Cup semi-final win at Tynecastle.
March 26: Celtic clinch a third title in a row with a 5-1 win at Firhill.
May 22: Resigns as the Celtic manager, seeking a new challenge.