Copenhagen-based Mercyful Fate is a Danish heavy metal group that was founded in 1981 by guitarist Hank Shermann and vocalist King Diamond. Along with Venom and Bathory, Mercyful Fate was a part of the initial wave of black metal in the early to mid-1980s. They were influenced by progressive rock and hard rock, and their songs dealt with Satan and the occult. Several groups from this style later influenced black metal musicians in the 1990s, especially in Norway. The 1980s and 1990s heavy metal movement, which included thrash metal acts like Metallica, Slayer, Testament, Exodus, and Kreator as well as death acts like Death, Morbid Angel, Obituary, and Cannibal Corpse, has also been credited as having been heavily influenced by Mercyful Fate.
Four out of the five members of Mercyful Fate reunited in 1992 to record the album In the Shadows, which was released the following year, after splitting up in 1985 due to musical differences. The band went through multiple line-up changes and added four additional studio albums during the 1990s. Mercyful Fate took a break in 1999, but they occasionally came back together in the 2000s. Mercyful Fate announced their more-permanent reunion on August 1, 2019, and they have plans to tour and release a new album their first since 9 in 1999.