Sir Alex Ferguson has revealed that he vowed to win back the title from Manchester City before retiring.
In his autobiography 'My Autobiography' Ferguson details how he was left devastated on the last day of the 2011/12 season when Manchester City stole the title away from Manchester United with two injury time goals against QPR.
According to the Guardian, Ferguson also reveals that his wife, Cathy, told him that the last day of that campaign was the worst of her life.
The manner in which the title was lost left Ferguson determined to win the title back off their City rivals before retirement.
The retired Manchester United manager also stated that he thought his team "absolutely battered" City in the 6-1 defeat to Old Trafford and were unlucky to lose by such a huge margin.
During the launch of his book, Ferguson reiterated the difficult time by saying losing the title to Manchester City was the worst setback to occur in his 27 years in charge at Old Trafford.
He told reporters: "Of all the setbacks I endured, nothing compared to losing the league to City."
In his book he also criticised former Manchester City boss Roberto Mancini for allowing Carlos Tevez to return to the squad following the incident against Bayern Munich, saying the Italian manager "let himself down."