Metallica may be the biggest band in metal, but Iron Maiden has to be among the best.
For just under forty years, the Steve Harris-helmed juggernaut has gone onto be a brand in and of itself, often being one of the first things that comes to mind whenever the pop-culture mainstream thinks of the phrase "heavy metal".
With their roots dating back to the celebrated New Wave of British Heavy Metal, the operatic and theatrical Maiden quickly set the precedent for generations of rock n' roll bands to come, mixing the technical acumen of old-school prog, the charisma of acts like Kiss and Alice Cooper and the hard-hitting attitude of punk.
Transcending their contemporaries massively, the band (with their instantly recognisable mascot, Eddie, never far behind) are giants of the rock realm, with such perfect albums as The Number of the Beast (1982), Powerslave (1984), Seventh Son of a Seventh Son (1988) and, more recently, Brave New World (2000) to their name.
Their back-catalogue is one of the most impressive in all of metal, so of course the classic rockers (as intelligent and culturally clued-in as they always are) found the time to sneak some little in-jokes, references and treats for the hardcore fans into their output.
This is a list of just some of them.
Some of these little details have been hiding in plain sight for up to thirty years, and they can all be found simply by sticking in a Maiden record and paying close attention.