On April 15 2003, the Blues clinched promotion to the Premier League with a 1-0 Fratton Park win over Burnley.
Twelve days later, they defeated Rotherham, also at home, to be crowned Championship champions.
And following a final day 5-0 romp at Bradford City, Blues fans came out in their thousands on Sunday, May 11.
For that was the day an open-top bus parade was held around the city, taking the players and management from Guildhall Square to Southsea seafront.
Now you can relive those heady weeks of seemingly non-stop celebrations with this nostalgia-packed photo gallery.
1. Pompey supporters celebrate promotion after beating Burnley
Picture by Jonathan Brady Photo: -
2. Fans on Southsea Common awaiting the Pompey team coach
Picture by Malcolm Wells Photo: -
4. Pompey's promotion party on the steps of the Guildhall
Picture by Malcolm Wells Photo: -
1 / 9