The concept of the song "The Loneliness Of The Long Distance Runner" off the Somewhere In Time album is adapted from the 1962 film of the same name.
In the album Fear Of The Dark, the track "Space Station No. 5" (1995 bonus CD) contains a hidden track entitled "Bayswater Ain't A Bad Place To Be" (previously available as a hidden track on the UK single of Be Quick Or Be Dead).
Somewhere In Time is the first Iron Maiden album that features guitar synthesizers, and Seventh Son Of A Seventh Son was the first where they used keyboards.
In the album Piece Of Mind, at the beginning of the sixth track, "Still Life", the band included a hidden message which could only be understood by playing the album backwards. This was a joke and an intended swing back at the critics who had accused Iron Maiden of being satanic. The backwards-message (see Wiki: Backmasking) features Nicko McBrain mimicking Idi Amin (or rather mimicking John Bird mimicking Idi Amin) uttering the phrase, "What ho said the t'ing with the three 'bonce', do not meddle with things you don't understand..." followed by a belch. The phrase itself is taken from the satirical album The Collected Broadcasts Of Idi Amin by Bird and Alan Coren. "What ho" and "What ho said the t'ing" are phrases that also crop up regularly on McBrain's "Listen With Nicko!" tracks from The First Ten Years collection.
The cover of The Number Of The Beast was originally created for the song "Purgatory", but the band's manager, Rod Smallwood, deemed it of too high a caliber for a single release and decided to save it for the full-length album instead. The original 1982 artwork includes a light blue sky in the background; this was a mistake by the printers of the album cover, and was later rectified and became black when the album was remastered for compact disc in 1998.
Music press reports told a story that during the recording sessions of The Number Of The Beast, there were instances of unexplained phenomena occurring. Lights would periodically trip out and there were "cold spots" in the studio. This all climaxed when the producer Martin Birch was involved in a car accident and was presented with a repair bill for £666.
The Number Of The Beast is one of two Iron Maiden albums listed in 1001 Albums You Must Hear Before You Die (Iron Maiden being the other).
Killers is the only Iron Maiden album to feature two instrumental songs ("The Ides Of March" and "Genghis Khan").
"Wrathchild" is featured in the PlayStation 2 game Guitar Hero Encore: Rocks The 80's.
On the 1998 re-release of the Iron Maiden debut, the fade out of "Transylvania" and the intro to "Strange World" were put at the end of "Transylvania", originally both the beginning of "Strange World".
Iron Maiden have released 145 original studio songs, here are the members' contribution to music/lyrics:

Steve Harris - 121
Bruce Dickinson - 42
Adrian Smith - 34
Janick Gers - 25
Dave Murray - 20
Nicko McBrain - 1
The song "To Tame a Land" is about Frank Herbert's highly-acclaimed sci-fi book Dune. While it was the band's intention to name the song after the novel, Frank Herbert abhorred heavy metal (and Iron Maiden in particular) so much at the time that he threatened to sue if they used the title.
Steve Harris used to play in the youth West Ham United football team in the 70's as mid or striker and is still considered a great amateur football player.
The lyrics to the song "Man on the Edge" were inspired by the film "Falling Down".
According to notes on The Number of the Beast, the members of Iron Maiden once faced the members of Scorpions in a soccer/football match. They tied, 1-1.
Iron Maiden recruited another guitarist in 1977, Bob Sawyer, who caused a rift between Murray and Wilcock, prompting Harris to fire both Murray and Sawyer. A poor gig at the Bridgehouse in November 1977, with a makeshift line-up including Tony Moore on keyboards, Terry Wapram on guitar, and drummer Barry Purkis resulted in Harris firing the entire band. Dave Murray was reinstated and Doug Sampson was hired as drummer.
Steve Harris started Iron Maiden after leaving his former group, Smiler. Harris attributes the band name to a movie adaptation of The Man in the Iron Mask, which he saw around that time, and so the group was christened after the purported torture device.
Having sold over 100 million albums worldwide. The band won the Ivor Novello Awards for international achievement in 2002. They were also inducted into the Hollywood Rock Walk during their tour in the United States in 2005.
Alongside his Iron Maiden duties, vocalist Bruce Dickinson also works as a pilot for the British airline, Astraeus.
The pub appearing on the cover of the album Killers, just behind Eddie, is the pub "Ruskin Arms" best known as one of Iron Maiden's first venues.
In the album "Powerslave", if you look carefully the hieroglyphics on the pyramids, you'll see "encoded" the words "Bollocks", "Indiana Jones was here" and "Wot, no Guinness?"
The songs "Back in the Village" and "The Prisoner" are based on the '60s TV show "The Prisoner", which both Steve Harris and Adrian Smith liked to watch.
The track "Aces High" is based on World War II dogfights.
The song "Brave New World" is based on the novel of the same name by Aldous Huxley.
Eddie's full name is Eddie The Head -or Edward The Head- and it comes from the following old joke:
Eddie was born with no body and no arms and no legs. Just a head. But despite this slight birth defect his parents loved him very much. So on his sixteenth birthday they run into a doctor that says "Hey, I can give Eddie a body"... so the parents are going totally nuts because finally their kid can have a body and be like other normal people. They go home and are really excited and say "Have we got a surprise for you. It's the best present ever!" and Eddie says "Oh, no, not another fucking hat!"

The original Eddie was just a theatrical mask. It can be seen in the band photos on the first album and on the "Running Free" single picture sleeve. It was a face right next to the band's logo. It was connected to a pump that would eject various kinds of liquids, from food dye to paint, and would drool over Doug Sampson, Clive Burr or whoever was at the drums at the time. Fans would also try to throw stuff into the mouth at gigs.
The song Where Eagles Dare is based on the 1968 classic WWII movie of the same title, starring Clint Eastwood and Richard Burton.
The song Como Estais Amigo is a tribute to the dead Argentinian soldiers in the Falkland Islands conflict between Argentina and England in 1982.
The song "Sign Of The Cross" is based on the book "The Name Of The Rose" (written by Umberto Eco).
Dave Murray started the 'Charlotte Saga' on 'Iron Maiden' (1980) by writing the song "Charlotte the Harlot" about a prostitute in the East End of London. This was continued on 'Number of the Beast' (1982) with the song "22 Acacia Avenue" and the 'No Prayer for the Dying' (1990) song "Hooks in You". "From Here to Eternity", on 'Fear of the Dark' (1992), also mentions Charlotte, although as this is in passing it is not regarded as being a true part of the saga.
The song "Rime of the Ancient Mariner" is based on the poem of the same name written by Samuel Taylor Coleridge. And although the song is perhaps Iron Maiden's longest studio track, it barely scratches the surface of the poem on which it's based.
The song "The Trooper" is about the Charge of the Light Brigade at the battle of Balaklava and is based on a poem written by Lord Alfred Tennyson.
The live keyboardist, not officially a band member, is named Michael "Count" Kenney.