Ken Bates famously bought Chelsea for just £1. Ken Bates, who has died aged 94, was one of the most colourful, controversial - and highly significant - figures in the modern football era. Bates was best known for his ownership of Chelsea over more than two decades of turbulence and success, buying the club for £1 in 1982 before selling to Roman Abramovich in a £140m deal in July 2003.

He started his time in football as chairman of Oldham Athletic in the 1960s, becoming owner and vice-chairman of Wigan Athletic in the early '80s before purchasing Chelsea. After selling the Blues to Abramovich, Bates became principal owner of Leeds United in January 2005, another stormy reign before leaving the club in July 2013.

Bates, a self-made millionaire from haulage and ready-mix concrete who was never shy of confrontation or an explosive quote, was also a member of the Football Association (FA) executive committee, emerging as a highly influential figure in the rebuilding of Wembley Stadium. He was appointed chairman of Wembley National Stadium Limited in 1997 but resigned four years later, claiming he had not been supported and that progress was too slow.

It was at Chelsea and Stamford Bridge where Bates came to nationwide prominence, as he took on a fallen giant in danger of extinction, inheriting debts of £1.5m but intent on turning their fortunes around. Chelsea faced bankruptcy when Bates walked in, but by the time he ceded control to Abramovich they had become a powerful force at home and abroad, winning the FA Cup twice, the League Cup and European Cup Winners' Cup in 1998, and the Uefa Super Cup.

The winning goal in that Cup Winners' Cup final against Stuttgart was scored by Gianfranco Zola, one of many European superstars to arrive at Chelsea during Bates' transformation of the club. From counting the pennies in his early years, Chelsea developed enough stardust to attract the likes of Ruud Gullit, Marcel Desailly and Gianluca Vialli - player-manager that night - to Stamford Bridge.

It was all a far cry from when Bates took over, but even then his acumen enabled him to provide funds for Chelsea to buy players of the calibre of Pat Nevin, Kerry Dixon and David Speedie to propel them towards being a top-flight force once more.

In 1985, Bates erected perimeter fencing at Stamford Bridge featuring an electrified section at the top in a bid to combat hooliganism - though it was never turned on for safety reasons. Bates was never far from controversy, especially in the mid-'80s when he erected a 12ft 12-volt electric fence around Stamford Bridge to prevent pitch invasions - but was then refused permission by Greater London Council to switch it on, citing safety grounds. In 1991, Chelsea were fined £105,000 for alleged illegal payments to players. Bates resigned from the Football League management committee.

He regarded one of his most significant achievements at Chelsea as securing Stamford Bridge as the club's home before developing it into a luxury all-seater stadium with a 40,000-plus capacity. It came after a long-running legal battle with property developers Marler Estates, which owned a substantial part of the stadium's freehold. He then started the Chelsea Pitch Owners scheme, sharing out ownership of the land with fans, ensuring Stamford Bridge would not be in similar peril again. This, in many respects, was as important as the success Chelsea eventually enjoyed during his tenure.

Bates was helped in his quest to bring the best players to Chelsea by the investment of Matthew Harding, who became a director in 1993 and eventually vice-chairman. Glenn Hoddle was appointed player-manager in June 1993 as the club became increasingly fashionable, doing well enough to be appointed England manager two years later.

Harding was a lifelong Chelsea fan who yearned for a return of the club's glory days, initially providing £5m for Stamford Bridge's renovation, then more money for players, but often clashed with Bates over the direction and power base of the club, eventually being banned from the Chelsea boardroom in 1995. Amid bitterness, the pair never reconciled before Harding's death in a helicopter crash returning from a League Cup tie at Bolton Wanderers.

Bates sacked Gullit, who had won the FA Cup the previous season, in February 1998 after their relationship suffered a fracture - with claims that the manager learned of his sacking via Teletext. Vialli replaced Gullit, bringing that European Cup Winners' Cup success to Chelsea, as well as an FA Cup final victory against Aston Villa in 2000.

Bates wielded the axe ruthlessly after Chelsea won only one of their first five league games the following season, although the decision brought heavy criticism from Pierluigi Casiraghi, the Italian striker bought by Vialli whose career was ended by injury. He said: "Ken Bates does not know the meaning of gratitude. He is arrogant and has made a mistake."

Even Bates' programme notes were required reading as he settled scores in print and used them to mount a fierce defence of either personal criticism or criticism of the club. Claudio Ranieri was Bates' final managerial appointment before selling to Abramovich, saying the deal would "take Chelsea to the next level" - which it duly did.

It turned out to be one of defining moments in Premier League history, as a succession of rich foreign owners bought in. Bates (right) replaced outgoing chairman Gerald Krasner when he took control of Leeds in 2005.

Bates insisted he was ready for "one last challenge", which he found at another 1970s football powerhouse in reduced circumstances - Leeds United. His former club quickly found themselves in his sights in August 2006 when Bates complained to the Football League that Chelsea were making illegal approaches to young Leeds players. Chelsea then reported Bates to the FA for comments he had made about the directors, the issue eventually being settled privately.

In keeping with the rest of his career, Bates' time at Leeds was a headline-grabber, going through five managers. A 3-0 defeat by Watford in the 2006 Championship play-off final under Kevin Blackwell proved pivotal. With no Premier League riches, Leeds went into voluntary administration the following year and were relegated to English football's third tier for the first time.

At this point, Leeds had debts of £30m, including about £7m owed to HM Revenue & Customs (HMRC). Leeds were handed a 10-point deduction which confirmed their relegation to League One, where they were hit with a further 15-point penalty. Bates was part of a consortium that bought the club back from the administrators. Leeds returned to the Championship in 2010, with Bates selling the club in 2012.

In later years Bates lived in Monaco, but still played host to journalists and was willing to share his outspoken views that made him such a compelling, controversial figure.