2003–04 FA Premier League

The 2003–04 FA Premier League season was the twelfth season of the Premier League. In the end, Arsenal went through the season without a single defeat – the first team ever to do so in a 38 game league season and the second team overall (the first was Preston North End in 1889, 115 years earlier, during a 22 game league season) and were crowned champions once more, at the expense of Chelsea, who had spent heavily throughout the season.

Chelsea had been bolstered by a £100 million outlay on world-class players, a spree funded by the extensive financial resources of their new owner Roman Abramovich. Manchester United's attack was as strong as ever thanks to free-scoring Ruud van Nistelrooy, but the midfield was weakened following the pre-season £25 million sale of David Beckham to Real Madrid, and the centre of defence suffered a more severe setback after Rio Ferdinand was ruled out for the final four months of the season after being found guilty of the "failure or refusal to take a drugs test". The case of Rio Ferdinand started a debate about punishments relating to drug testing in football, with there being differing views on whether the punishment was too harsh or too lenient. Ferdinand's club sought to make direct comparisons with an earlier case of Manchester City reserve player who had in fact committed a lesser drug testing offence and as a result escaped with only a fine. City themselves had just moved from Maine Road to the state of the art City of Manchester Stadium.

Arsenal, meanwhile, had only signed German goalkeeper Jens Lehmann in the 2003 close season, but French striker Thierry Henry was instrumental in Arsenal's success. Away from the Premiership, Arsène Wenger's team suffered disappointment in the cup competitions. They lost their defence of the FA Cup (which they held for two seasons in a row) after losing to eventual winners Manchester United in the semi-final. Arsenal were knocked out of the Champions League quarter-finals by Chelsea (3–2 on agg). These two blows came with a few days of each other and it was feared that Arsenal might squander their lead of the Premiership for the second successive season, but Arsenal thumped Liverpool only days later. Arsenal's Invincibles finished the season with 26 wins, 12 draws, 0 defeats and 90 points.

The three relegation spots were occupied by three teams bracketed together on 33 points. Wolves and Leicester City followed the trend of many other newly promoted Premiership clubs and were relegated just one season after reaching the top division. But the other relegation place went to Leeds United, whose playing fortunes had dipped in the past two seasons after David O'Leary was sacked as manager and club debts had risen so high that many star players had to be sold. As a result, Leeds were finally relegated from the Premiership after 14 years of top division football – just three seasons after they had reached the Champions League semifinals.

In his third season as Middlesbrough manager, Steve McClaren had guided the Teessiders to their first ever major trophy – sealed with a 2–1 win over Bolton Wanderers in the League Cup final. McClaren was also the first English manager to win a major trophy since Brian Little guided Aston Villa to League Cup success in 1996. He was also the first manager to take Middlesbrough into European competition – they would be competing in the 2004–05 UEFA Cup.

2003–04 saw a number of managerial changes in the Premiership. Glenn Hoddle was sacked as manager of Spurs in September, with Director of Football David Pleat taking over as temporary manager until the end of the season. He was then replaced by French national coach Jacques Santini, who was in the charge for five months before being replaced by assistant first team coach Martin Jol. At the end of 2003–04, Frank Arnesen was appointed Director of Football for Spurs.

Leeds United sacked Peter Reid in November and installed first team coach Eddie Gray as interim manager until the end of the season, as they could not afford to buy another team's manager out of his contract. Gray was unable to save Leeds from relegation and was sacked by the club's new owners, who installed Gray's assistant Kevin Blackwell as their new manager.

Gordon Strachan quit as Southampton manager in March and was replaced by Plymouth Argyle's Paul Sturrock. Just after the start of 2004–05, Sturrock handed in his resignation and was replaced by Steve Wigley who spent three months at the helm before being replaced by Harry Redknapp.

At the end of 2003–04, Gérard Houllier was sacked as manager of Liverpool despite having won four cup competitions (including three in one season) during his six-year spell as manager. Liverpool then turned to ex-Valencia coach Rafael Benítez as the man they hoped could win the league title which has eluded Anfield since 1990.

Despite guiding Chelsea to second position in the Premiership (their highest league finish for half a century) and to their first ever Champions League or European Cup semifinal, Claudio Ranieri was sacked after four years in charge at Stamford Bridge. Roman Abramovich then appointed José Mourinho as Chelsea's new manager. Mourinho, who won the 2004 Champions League with Porto of Portugal, was given a three-year contract.