Background, writing and recordingEdit
"Empire of the Clouds", at 18 minutes in length, is Iron Maiden's longest song to date, overtaking "Rime of the Ancient Mariner" from their 1984 album, Powerslave The track tells the story of the R101 airship, which crashed on its maiden voyage in northern France on 5 October 1930. The song was written solely by the band's lead vocalist, Bruce Dickinson, who initially intended it to be about "World War I fighter airplanes" but was forced to change this after writing the lyrics to "Death or Glory" (also from The Book of Souls), which had the same theme. At the time of recording, Dickinson was reading "a big, sort of encyclopedic crash report" of the R101, entitled To Ride the Storm, which gave him the idea for the song's eventual subject, as well as the first line of lyrics. Dickinson describes it as "A very poignant story, a very human story, a story of ambition and dreams."
Dickinson largely composed it during The Book of Souls' recording sessions at Guillaume Tell Studios, Paris. According to one of the group's guitarists, Adrian Smith, Dickinson "was working on it for about a month on his own" in a sound-proof booth. The track features Dickinson's debut on piano, as he used the studio's Steinway grand piano to write the song, although he used a keyboard on the actual recording, thereby making it easier to edit out his mistakes.
According to Smith, the song was a challenge for the rest of the band as they had to play along to Dickinson's piano track while following his and producer Kevin Shirley's instructions. In addition to the band's parts, additional orchestration was added to the song afterwards, while Nicko McBrain experimented with a variety of percussive instruments, including a bowed gong, to recreate the airship's crash.
On 11 March 2016, the band announced that the song would be released as a 12" picture disc single for Record Store Day limited to 5,500 copies, using the front cover of the Daily Mirror from 6 October 1930 as the cover artwork. The single's B-side features an interview with Dickinson and McBrain, entitled "Maiden Voyage", in which they recount the song's creation.