There are apparently at least 19 different versions of this film, starting with the original 6-hours cut (in a "triptych" format, requiring three projectors on three screens, called Polyvision). It has been shown in various formats and different running times, including a 1934 version re-edited by director Abel Gance and featuring an added soundtrack.
The film was deemed lost until film historian Kevin Brownlow managed to locate and restore many segments from various sources. In 1981 it was finally reissued in a 235-minutes version with a new music score by Carmine Coppola.
In 2000, film historian Kevin Brownlow prepared an even longer version of "Napoleon" (over 5 and a half hours) with improved film footage replacing existing footage, newly acquired segments, color tints, etc., bringing the film even closer to its original form. This newly restored version has been shown theatrically in England.
The first film with stereophonic sound was the re-edited version of this film that was presented with added dialogue and sound effects at the Paramount Cinema, Paris, in 1935. The stereophonic process used had been patended by Abel Gance and Andre Debrie three years earlier.
A copyright dispute over which music soundtrack should be performed with "Napoleon" exists between Zoetrope Studio/Francis Ford Coppola and the BFI/Kevin Brownlow/Carl Davis. When Brownlow assembled the original restored version in 1981 two scores were eventually produced, one (for the American market?) by Carmine Coppola (Francis' father and composer of the Godfather scores) and another (for the UK market?) by Carl Davis, veteran of many new scores for old silent movies. Prior to two live performances of the Davis score in December 2004 to accompany a new 5hr+ restoration of Napoloen, Coppola attempted to prevent the performances going ahead without his late father's score on the grounds that his family owns the copyright over the film, even though carmine Coppola's score was written for the short 4hr restoration. In the end the perfomances went ahead with Davis' score being used, although the dispute remains unresolved. It is uncertain whether Davis' score will ever be heard again while the dispute remains ongoing.