Italian football had been rocked by several scandals down through the years but nothing compared to Calciopoli, which saw champions Juventus stripped of not one but two titles and relegated to Serie B for the first time in their history.
Essentially, an investigation into the football agency GEA world revealed attempts by the Bianconeri, AC Milan, Fiorentina, Lazio and Reggina to influence the appointment of referees to Serie A fixtures.
The Rossoneri were hit with a 30-point deduction for their involvement and that resulted in the 2005-06 Scudetto being awarded to third-placed Inter. Juve’s 2004-05 title triumph was also revoked but was not assigned to another club.
The whole affair remains a bitterly divisive issue today, with the Bianconeri insisting that they were made the scapegoats in a scandal that later evidence suggested involved many other clubs, including Inter.
Indeed, Juve boss Fabio Capello still maintains, “The [titles] were then taken away from us, but we won them on the pitch."
Juventus pulled off a major coup by signing France midfielder Patrick Vieira from Arsenal but it was Fiorentina’s Giorgio Chiellini who would actually prove the more significant acquisition in the long run, as the former would end up defecting to Inter after just one season in Turin.
Despite already being in possession of Andriy Shevchenko and Pippo Inzaghi, Milan strengthened their attack with Alberto Gilardino and Christian Vieri. The prolific Parma forward Gilardino had a decent debut season at San Siro but it quickly became evident that Vieri’s best days were well and truly behind him.
Inter made a couple of excellent additions to their defence in the shape of Brazilian goalkeeper Julio Cesar and Argentine centre-half Walter Samuel, while they also snapped up Luis Figo on a free transfer.
The most notable changes in the capital both came on the bench, with Roma appointing Luciano Spalletti as their new coach, and Lazio hiring Delio Rossi.
Fiorentina, meanwhile, brought in Cesare Prandelli, who constructed an excellent side around the goalscoring brilliance of their €10 million summer signing from Palermo, Luca Toni.
Juventus made a storming start to the defence of their title, winning nine games in a row until they were beaten 3-1 at San Siro by second-placed Milan. That victory drew the Rossoneri to within two points of the league leaders but they were unable to keep up with the Bianconeri, who had a record-breaking 52 points by the midway point of the season.
By that stage, Inter had climbed into second place. However, after a fantastic run of 11 wins from 12 games, which included a dramatic 3-2 win over Milan in the Derby della Madonnina, the Nerazzurri's title challenge was ended by back-to-back losses to Fiorentina and Juve in February.
Milan hadn't gone away, though, and Carlo Ancelotti's side took advantage of Juve's remarkable run of five successive draws to draw to within three points of the Old Lady with three rounds remaining.
However, Juve held their nerve wonderfully well, beating Siena, Palermo and Reggina to claim their second consecutive Scudetto. Or so they thought. After Calciopoli, Juve were stripped of two titles and demoted to last place in the 2005-06 season.
The Bianconeri’s relegation changed the entire course of Serie A history as Capello, Fabio Cannavaro and Emerson all departed for Real Madrid, while Zlatan Ibrahimovic and Vieira joined Inter, whom they would help become the new major force in Italian football.
PLAYER OF THE SEASON
After his dismal stint at Inter, the centre-half got back to his brilliant best at Juventus and had the year of his life in 2006, helping Juve win the title - at least on the field - before then captaining Italy to World Cup glory in Germany that summer.
MANAGER OF THE SEASON
Capello may have won the title again, while Roberto Mancini lifted the Supercoppa Italiana and Coppa Italia but Luciano Spalletti impressed all and sundry by leading Roma to a fifth-placed finish - later upgraded to runners-up - thanks in no small part to an 11-game winning run during the second half of the season.
LUCA TONI - 31 GOALS
In his first season at the Artemio Franchi, the Fiorentina forward became the first player since Antonio Valentin Angelillo in 1969 (33) to break the 30-goal barrier in Serie A by netting 31 times for the Viola.
GOAL OF THE SEASON
FRANCESCO TOTTI produced the goal of the season, leaving two Inter trailing in his wake in their clash at San Siro before cutting inside another and then coolly chipping the goalkeeper from 25 yards out.
MOST EXPENSIVE TRANSFER
Parma to Milan
KEY MOMENT OF THE SEASON
After five successive draws, Juve desperately needed to get back to winning ways at Siena to keep a resurgent Milan at bay. The Bianconeri did just that, scoring three times in the opening eight minutes through Vieira, David Trezeguet and Adrian Mutu, and never looked back.