"When You Believe" was recorded by The 2007 X Factor winner Leon Jackson.
"When You Believe" is a song from the 1998 DreamWorks musical animated feature The Prince of Egypt., written and composed by Stephen Schwartz. A pop single version of "When You Believe", with additional music and lyrics by writer-producer Babyface, was also recorded for the film by American singers Mariah Carey and Whitney Houston for the film's end credits and its soundtrack album. The original version of the song, featured in the narrative portion of the film, is performed by Sally Dworsky, Michelle Pfeiffer, and a children's choir. "When You Believe" is described as a big ballad, with meaningful and inspirational lyrics, describing the ability each person has to achieve miracles when they reach out to God and believe.
The single was available to download from midnight after the result of the show on December 15, 2007, and a CD was rush-released mid-week, on December 19, 2007. This is unusual as most new singles are released on a Monday to gain maximum sales for the UK Singles Chart the following Sunday. Exceptions included the previous two X Factor winners whose were singles released in this fashion, in order for them to compete to be the Christmas number-one single, which they all became. A video for the single was made by each of the final four of the series; Jackson, Rhydian Roberts, Same Difference and Niki Evans. However, only the winner's version of the song and video was released.
On December 23, 2007, it debuted at number one on the UK Singles Chart, making it the coveted Christmas number one with sales of over 275,000 copies. It stayed at number one for three weeks until it fell down to number five on its fourth week and then fell another ten places to number fifteen in its fifth week. The song ended 2007 as the year's fourth biggest-selling single in the UK. According to The Official Charts Company, the song has sold 506,000 copies in the UK as of December 2012.