Big Brother divorcees Chantelle Houghton and Preston were reunited as they joined the star line-up for the final series.
The couple, who met on the celebrity version of the show and married after a whirlwind romance, were among 11 contestants who joined Ultimate Big Brother last night.
Also among the group was Co Kildare's Brian Dowling, who won the show's second series.
The show kicked off just moments after the winner of Big Brother 11 was announced, with victor Josie shocked to learn she was being thrown straight into another series.
Other housemates in the series -- which will run for 18 days before the reality show leaves Channel 4 for good -- include CBB champion Ulrika Jonsson, rapper Coolio and racing pundit John McCririck.
Sparks could fly with the reunion of Coolio and Jonsson who were noted for their fractious relationship when they appeared together in Celebrity Big Brother 6 last year.
Also joining the last hurrah was anti-hero 'Nasty' Nick Bateman, who notably became the first person to be disqualified from the show during the first series in 2000 after trying to influence nominations.
He was booed by the crowd as he entered the house wearing a T-shirt which read 'It's only a gameshow'.
Completing the group were Makosi Musambasi, transsexual former winner Nadia Almada and Nikki Grahame.
The moment Nikki walked into the house McCririck told her: "None of your tantrums with me."