Def Leppard formed in Sheffield, England in 1977 as Atomic Mass with original members Rick Savage, Pete Willis and Tony Kenning.
Frontman Joe Elliot came into the picture not long after and the band adopted the name Deaf Leopard, soon altering the spelling to be "more rock 'n' roll".
Additional guitarist Steve Clark (the 17-year-old son of a Sheffield taxi driver) joined just in time for their first gigs in July 1978 and Frank Noon replaced Kenning prior to recording their first single.
With finance provided by Joe's father, the band released a debut EP entitled Getcha Rocks Off in 1979 on their own Bludgeon Riffola label.
Later that year, with Rick Allen taking up permanent residence on the drum stool, and following tours supporting AC/DC and others, the band were signed to Vertigo which prompted a move to London, and in 1980 their debut album On Through The Night broke into the UK Top 20.
The band were certainly metal (albeit metal of the most easy listening variety) and while the critics hated them, their growing army of fans lapped up every release.
Although High 'N' Dry (1981) marked the beginning of their association with Mutt Lange, Def Leppard's big break came with 1983's Pyromania.
Legendary for use of all manners of studio special effects and state-of-the-art technology, the record revolutionised heavy metal and became the benchmark by which subsequent 80s albums were measured.
It would, however, be America that eventually embraced the band. Highly melodic and extremely hook-laden, the Americans loved Pyromania and it's attendant singles Photograph and Rock Of Ages, with the album selling over seven million copies.
Tragedy struck when Rick Allen crashed his Corvette Stingray during an ill-timed high-speed argument with another driver outside Manchester on New Years Eve 1984. Trying to pass the other car, Allen slammed his Corvette into overdrive, hit a sudden curve too fast and crashed into a brick wall.
His left arm was torn off by the impact, and although surgeons re-attached the limb they had to amputate it three days later when infection set in. A true metal warrior, Allen soldiered bravely on using a customised drum kit with programmable drum pads and foot pedals.
Bearing in mind his accident and the band's perfectionist nature, four years wasn't too long to wait for a new album . . . and for the majority of fans, the delay was well worth it.
A melodic rock tour de force, the Hysteria (1987) album finally broke the band in their home country with three of its singles reaching the UK Top 10 and Love Bites giving the band their very first #1.
Similarly successful across the Atlantic and worldwide, the album sold a staggering amount with Def Leppard staking their claim as the biggest heavy metal act on the planet.
Ironically, just as the group were entering the big league, tragedy struck again as Steve Clark was found dead in his Chelsea apartment on 8 January 1991 after a prolonged drink and drugs binge.
The official cause of death was recorded as 'compression of the brain stem as a result of mixing alcohol with prescription anti-depressants and painkillers'. He was only 30.
The band recruited Belfast-born elder statesman of rock, Vivian Campbell, as a replacement and began work on the Adrenalize (1992) album. While the single Get Rocked bordered on cringeworthy, the album's glossy pop metal once again pulled in the punters in their millions.
The next few years saw the release of a B-sides/rarities affair called Retro Active (1993) and a greatest hits collection, Vault (1995). A new studio album, Slang, eventually hit the shops in 1996, showcasing a more modern sound - and some updated hairstyles.