On this day in 1987, Def Leppard had their first number one album in the UK with Hysteria. It would take just under a year for the record to top the charts here in the US. Hysteria is the fourth studio album by Def Leppard, and is the band's best-selling album to date, selling nearly 30 million copies worldwide, including 12 million in the US, and spawning seven hit singles. The album charted at #1 on both the Billboard 200 and the UK Albums Chart. Hysteria was produced by Robert John "Mutt" Lange. The title of the album was thought up by drummer Rick Allen, referring to his 1984 auto accident and the ensuing worldwide media coverage surrounding it. It is also the last album to feature guitarist Steve Clark before his death, although songs co-written by him would appear on the band's next album, Adrenalize. The album is the follow-up to the band's 1983 breakthrough Pyromania. Hysteria's creation took over three years and was plagued by delays, including the aftermath of the 31 December 1984 car accident that cost drummer Rick Allen his left arm.