The fourth series was broadcast on ITV from 18 August 2007 and was won by Leon Jackson on 15 December 2007, with Rhydian Roberts finishing as the runner-up and Dannii Minogue emerging as the winning mentor.
Fearne Cotton replaced Ben Shephard as presenter on the spin-off show The Xtra Factor.
The original judging panel consisted of Simon Cowell, Minogue, Sharon Osbourne and Brian Friedman.
[3] This, along with the additional category, created vacancies for two new judges to join the original panel of Sharon Osbourne and Simon Cowell.
Walsh was replaced by American choreographer Brian Friedman, who was hired after impressing Cowell on his show Grease Is the Word.
Cowell hired Minogue after viewing tapes of her judging on Australia's Got Talent, and because of her 30 years experience as a singer and performer.
[10][11] Commenting on Friedman's replacement by Walsh, Osbourne said that there was no "chemistry" within the original judging line-up, and that the atmosphere was "very uncomfortable".
[13] In an interview with ITV Head of Entertainment and Comedy, Paul Jackson, O'Leary said he was still getting used to handling the rejected at the auditions: "I'm still trying to work it out.
"[citation needed] On 2 May 2007, it was announced that Ben Shephard had quit his role as presenter of spin-off show The Xtra Factor on ITV2.
"[14] Shephard later signed up to front DanceX, a BBC One series hunting for a modern-day version of '70s dance outfit Hot Gossip.
[20] The locations for the round were confirmed during episode 8 on 29 September; they were later revealed by Louis Walsh not to be the judges' real homes.
[22][23] As in previous series, the judges were joined by an assistant to help them make their decisions: Cowell was joined by former pop star Sinitta; Osbourne by The Pussycat Dolls lead singer Nicole Scherzinger; Walsh by Westlife singer Kian Egan; and Minogue by songwriter and producer Terry Ronald.
Episode 9 was shown on Saturday 6 October where all 24 acts performed for a place in their mentor's top three and, subsequently, the live shows.
This is notable because at that time it was known as the first Sunday episode to be aired in X Factor history (excluding The X Factor: Battle of the Stars which aired over eight consecutive nights over a week) Boys: Groups: Over 25s: Girls: Key: The live shows commenced on 20 October 2007, a week later than in previous series.
During the results show she performed a premiere of her new single, "Bleeding Love", from her debut album, Spirit.
Westlife appeared on the sixth live show on 24 November singing "I'm Already There" from their 2007 album Back Home.
With the appointment of Friedman as choreographer, finalists used dance routines more frequently during their live performances in comparison to previous series.
[22] Contrary to reports about a change of venue, the live shows for this series continued to be broadcast from The Fountain Studios.
Unlike past series there was no dramatic change in the set, only minor alterations and space created for a larger audience.
The quarter-final did not feature a final showdown and instead the act with the fewest public votes, Hope, were automatically eliminated.
[33] The semi-final did not feature a final showdown and instead the act with the fewest public votes, Niki Evans, was automatically eliminated.
During the results of the first live show on 20 October, Osbourne walked away from the panel after it was revealed that both the bottom two acts came from her category.
[47][48] It later emerged that Osbourne was dissatisfied with the last-minute rescheduling of the programme from 17:45 to 17:30, claiming that fewer people saw the performance of her act, Kimberley Southwick, as she was first on stage.
[49][50] During the filming of The X Factor, there was much media speculation about rumoured feuds between the judges, most notably between Osbourne and Minogue.
Simon Cowell said at the ITV Autumn Launch: "We tried to be bit more impartial as judges, and that, you'll see a lot more of on X Factor.
"[65] Following girlband Hope's victory at judges houses, member Sisi Jghalef was eliminated prior to the live shows when it was discovered by the producers that she had an outstanding criminal conviction, thus violating the rules of the competition.
[66] Prior to auditioning as a solo artist, Jghalef had reportedly racially threatened a black McDonald's worker and failed to complete 200 hours of community service.
Following her elimination, she had reportedly tried to commit suicide by attempting to overdose on paracetamol: "If my mum hadn't found me I would be dead by now [...] I've managed to pull myself together [now] thanks to my friends and family", she told Mirror Online.
ITV denied the allegations, commenting that "As all numbers go through to the same lines and vote platform it is impossible for there to be any bias in favour or against a particular contestant.
"[69] ITV confirmed that Jackson performed strongly throughout the series and won on the night of the final by around 10% of the popular vote.