Former Liverpool FC boss Gérard Houllier has died aged 73 according to reports by French media.
The Frenchman managed Liverpool from 1998-2004, winning six trophies with the club with five of them all coming in 2001.
Houllier initially took charge as joint-manager with Roy Evans in an experiment that lasted less than six months before he was given the job outright in November 1998.The former school teacher was credited with dragging Liverpool into the 21st century with regards to their approach to training and preparation, bringing in more modern techniques that moved the Reds to the cutting edge of the game.
News of his death was announced by French news outlet: RMC Sport.
He went on to manage Aston Villa in 2010, but was forced to step away from the role in 2011 due to ill health.
In the October of Liverpool's successful 2001 season, he was rushed to hospital for emergency heart surgery after falling ill on the bench at a game against Leeds United.
Houllier's success at Liverpool led to him being named European Coach of the Year in 2001.
Houllier, who also managed Paris St Germain and Lyon during his career, did not return to day-to-day coaching after leaving Villa.
More recently, he worked as head of global football for the Red Bull group which owns RB Leipzig, RB Salzburg and the New York Red Bulls, as well as advising Lyon.
Honours won by Houllier at Liverpool:
FA Cup - 2001
League Cup - 2000-01; 2002-03
FA Charity Shield - 2001
UEFA Cup - 2000-01
UEFA Super Cup - 2001
Liverpool and the footballing world have been paying tribute to Houllier on social media.
Former Liverpool defender and Houllier's Assistant Manager, Phil Thompson, tweeted: "Absolutely devastated and heartbroken at the sad news of the passing of Gerard.
"My mate, my colleague, my boss. One of the greatest moments of my life was when we come together in 1998. Just to be in his company was an absolute treat. So loyal, so passionate and extremely fierce.
"So many wonderful times, bringing smiles back to peoples faces. 2001 should never be forgotten.
"Since we finished, at the end of every conversation we had, I told him I loved him and would always be grateful for him giving a wonderful partnership. RIP Boss."
Former defender Stephen Warnock, who played under Houllier at Liverpool and Villa, told Sky Sports News: "Very sad news, someone who obviously had a huge influence at Liverpool and with the French national team as well.
"My manager on two occasions and someone who I'll openly admit we didn't see eye to eye at times but this is terrible news and my thoughts, as I'm sure everyone else's, are with him and his family at this terrible time.
"We can see the reactions coming in straight away over social media from players who have played under him and managers alike who had huge amounts of respect for him for what he achieved in the game.
"He'll be remembered fondly by Liverpool fans for that incredible season where they won the treble of cups and went on to win five trophies in the calendar year."