Iron Maiden are an English heavy metal band formed in Leyton, East London, in 1975 by bassist and primary songwriter Steve Harris. The band's discography has grown to thirty-eight albums, including sixteen studio albums, twelve live albums, four EPs, and seven compilations. Pioneers of the new wave of British heavy metal, Iron Maiden achieved initial success during the early 1980s. After several line-up changes, the band went on to release a series of UK and US platinum and gold albums, including 1982's The Number of the Beast, 1983's Piece of Mind, 1984's Powerslave, 1985's live release Live

Iron Maiden were formed on Christmas Day in 1975 by bassist Steve Harris shortly after he left his previous group, Smiler. Harris attributes the band's name to a film adaptation of The Man in the Iron Mask from the novel by Alexandre Dumas, the title of which reminded him of the iron maiden torture device. After months of rehearsal, Iron Maiden made their debut at St. Nicks Hall in Poplar on 1 May 1976, before taking up a semi-residency at the Cart and Horses Pub in Maryland Point, Stratford.  The original line-up did not last very long, however, with vocalist Paul Day being the first casualty as, according to Harris, he lacked "energy or charisma on stage". He was replaced by Dennis Wilcock, a Kiss fan who used make-up and fake blood during live performances. Wilcock's friend Dave Murray was invited to join, to the dismay of the band's guitarists Dave Sullivan and Terry Rance. Their frustration led Harris to temporarily disband Iron Maiden in 1976, though the group reformed soon after with Murray as the sole guitarist. Steve Harris and Dave Murray remain the band's longest-standing members and have performed on all of their releases.  Iron Maiden recruited yet another guitarist in 1977, Bob Sawyer, who was sacked for embarrassing the band on stage by pretending to play guitar with his teeth. Tension ensued again, causing a rift between Murray and Wilcock, who convinced Harris to fire Murray, as well as original drummer Ron Matthews. A new line-up was put together, including future Cutting Crew member Tony Moore on keyboards, Terry Wapram on guitar, and drummer Barry Purkis (better known today as Thunderstick). A bad performance at the Bridgehouse, a pub located in Canning Town, in November 1977 was the line-up's first and only concert and led to Purkis being replaced by Doug Sampson. At the same time, Moore was asked to leave as Harris decided that keyboards did not suit the band's sound. A few months later, Dennis Wilcock decided that he had had enough with the group and left to form his own band, V1, and Dave Murray was immediately reinstated. As he preferred to be the band's sole guitarist, Wapram disapproved of Murray's return and was also dismissed.  Steve Harris, Dave Murray and Doug Sampson spent the summer and autumn of 1978 rehearsing while they searched for a singer to complete the band's new line-up. A chance meeting at the Red Lion pub in Leytonstone in November 1978 evolved into a successful audition for vocalist Paul Di'Anno. Steve Harris has stated, "There's sort of a quality in Paul's voice, a raspiness in his voice, or whatever you want to call it, that just gave it this great edge." At this time, Murray would typically act as their sole guitarist, with Harris commenting, "Davey was so good he could do a lot of it on his own. The plan was always to get a second guitarist in, but finding one that could match Davey was really difficult."

When did the record their first album?