The Damned United

After failing to qualify for the 1974 FIFA World Cup, England manager Alf Ramsey is replaced by Don Revie (Colm Meaney), the highly successful manager of Leeds United. Revie's replacement at Leeds is Brian Clough (Michael Sheen), the former manager of Derby County and a fierce critic of Leeds, because of their violent and physical style of play under Revie's management. Furthermore, Clough's longtime assistant, Peter Taylor (Timothy Spall), has not joined him.
The roots of Clough's conflict with Leeds are depicted as happening in a 1968 FA Cup match between Leeds, the leaders of the First Division[3] and Derby, who were struggling near the bottom of the Second Division. Clough, assuming Revie to be a similar man to himself, as they grew up in the same part of Middlesbrough and both played for Sunderland, made many preparations for the match; come the day of the match however, Revie failed to even acknowledge Clough upon entering the Baseball Ground. Derby eventually lost 2â0.[4] Although Clough initially blames the brutality of the Leeds players, he and Taylor recognise that their side are not good on a technical level. So they sign veteran Dave Mackay (Brian McCardie), along with several other young players. Chairman Sam Longson (Jim Broadbent) is extremely anxious about the investment, as well as the fact that Clough did not consult him before signing Mackay. However, in 1969 Derby are promoted. They once again face Leeds, only to lose 5â0. The club win their first ever League championship in 1972, meaning a European Cup campaign the following year. They go through to the semi-finals against Juventus. Unfortunately, against Longson's advice, Clough uses his best squad in the last match before the semi-final, against Leeds, purely out of pride and determination to beat Revie. They suffer injuries and Billy Bremner (Stephen Graham) sarcastically wishes Clough well for the semi-final. Juventus defeat them 3-1, and Clough publicly lambasts Longson.[5]
Taylor then suffers a heart attack, and Clough tries to secure his position by offering his and Taylor's resignations in a protest against the chairman's unwilligness to fund further signings. To his horror, the club accepts their resignations and bans them from entering the Baseball Ground again (although Clough later sneaks in as a supporter). Derby fans' outrage raises Clough's hopes of being reinstated, and he is backed by the majority of his players as well, but former player Dave Mackay is appointed manager instead. Derby fans quickly lose interest and Clough loses all hope of getting his job back. He and Taylor are then offered jobs at Brighton &amp; Hove Albion. They agree to take the jobs after taking an all-expenses-paid holiday in Majorca. During the holiday that summer, Clough agrees to take control of Leeds after being approached by their representatives.[6] Taylor, however, argues the case for staying at Brighton, and after a bitter quarrel, the two go their separate ways.
Back in the storyline's "presentâ. Clough alienates his players in their first training session, first by telling them that they can throw away any awards they have won because they "never won any of them fairly", and then making them start with a 7-a-side game, which Bremner points out Don Revie never made them do. Clough reminds them that he is not Mr Revie and threatens a severe punishment for any player who mentions the former manager's name or methods again.
The season starts with a Charity Shield match against FA Cup winners Liverpool at Wembley, which is widely anticipated as both the final match of Liverpool manager Bill Shankly and Clough's debut as Leeds manager. Unfortunately, the event is marred when Leeds's captain, Billy Bremner gets into a fight with Kevin Keegan. Both are sent off, and in turn throw their shirts off and walk off the pitch bare-chested in defiance. Leeds lose the match on penalties, and Bremner is given a two-month suspension from football, forcing Leeds to start the season without their influential captain. As a result, Leeds suffer a horrendous start to the season and are in danger of relegation only one season after winning the title. After Bremner and the players air their grievances to the board, the club terminates Clough's contract after just 44 days - though he forces them to pay an enormous severance package. Afterwards, Clough agrees to do a final interview with Yorkshire Television, but finds Revie there to confront him, bringing the two face to face at last. Clough accuses Revie of being 'cold-hearted' and 'fundamentally dishonest', both as a person and a football manager, and Revie in turn brands Clough as 'inflexible and egocentric'. Clough brings up the incident in the 1968 FA Cup, and Revie claims to have not known who the rookie manager was at the time (a doubtful claim considering that Revie was known for meticulously researching every opponent his team faced). After the interview, Clough drives down to Brighton to patch things up with Taylor. It involves Clough literally on his knees, grovelling at Taylor's dictation, and they are reconciled.
In the film's epilogue, the audience is told that Don Revie failed as England manager, and afterwards never worked in football in his home country again, spending the rest of his career working in the Middle East, where he was accused of financial mismanagement. Brian Clough and Peter Taylor, meanwhile, reunited at the 'small, provincial club' Nottingham Forest, where they repeated their prior achievements with Derby by taking them up and winning the First Division. They then bettered both Revie and their own spell at Derby by winning two European Cups in succession, in 1979 and 1980. The film ends by branding Clough "the best manager that the English national side never had".

Question: Who does Clough have a conflict with?
Answer: Leeds