Formation and first releases (1985–1987)
The King Diamond logo used on every album release since 1986.
The band was formed in 1985 by vocalist King Diamond, guitarist Michael Denner and bassist Timi Hansen. The three had recently departed from the group Mercyful Fate, which fell apart due to musical differences between King Diamond and guitarist Hank Shermann. According to Diamond, when he, Denner and Hansen decided to form a new band, they chose the name "King Diamond" to "get better deals", and because the name was already known from Mercyful Fate. To round-out the line-up of the King Diamond band, the group chose drummer Mikkey Dee and guitarist Andy LaRocque.
In July, 1985, the band began recording their debut album at Sound Track Studio in Copenhagen, Denmark. On December 25, they released their debut single "No Presents for Christmas". Fatal Portrait, the band's first full-length studio album, was released on February 17, 1986, through Roadrunner Records. Produced by Rune Höyer and vocalist King Diamond, the album charted at number 33 on the Swedish album chart, and spawned the single "Halloween", which was released on June 6, 1986.
In December 1986, King Diamond began recording their second studio album, once again at Sound Track Studio in Copenhagen, Denmark. Prior to the album's release, the group released the single "
The Family Ghost" on July 1, 1987, for which they also shot their first music video. On October 21, 1987, King Diamond released the album Abigail, their first concept album based on an original story by vocalist King Diamond. The album went on to chart at number 39 in Sweden, number 68 in the Netherlands, and at number 123 on the Billboard 200. Following Abigail's release, guitarist Michael Denner left the band due to touring strains. He was subsequently replaced by Mike Moon for the album's supporting tour, during which the band recorded the live album In Concert 1987: Abigail (however it wasn't released until 1990).
"Them" and Conspiracy (1988–1989)
Following the completion of the Abigail tour, guitarist Mike Moon and bassist Timi Hansen were replaced by Pete Blakk and Hal Patino respectively. On September 13, 1988, King Diamond released the album "Them", which was recorded at M.M.C. Studio in Copenhagen, Denmark. Another concept album, "Them" charted at number 38 on the Swedish album chart, number 65 on the Dutch album chart, and at number 89 on the Billboard 200, making "Them" King Diamond's highest charting album in America to date. Another music video was also shot, this time for the single "Welcome Home". On November 1, the group released The Dark Sides EP, a collection of previously released material as well as one unreleased track.
Following the completion of the supporting tour for "Them", Mikkey Dee left King Diamond. However, he was rehired to play drums on the band's follow-up album, after which he was replaced by Snowy Shaw. On August 21, 1989, King Diamond released the album Conspiracy, which charted at number 41 on the Swedish album chart, number 64 on the Dutch album chart, and at number 111 on the Billboard 200. A continuation of the storyline from "Them", Conspiracy was once again recorded at M.M.C. Studio. A music video was also made for the track "Sleepless Nights".
From The Eye to House of God (1990–2000)
In June 1990, King Diamond began recording fifth studio album at Sweet Silence Studios in Copenhagen, Denmark. The drums on the album were played by Snowy Shaw using drum pads. Released on October 30, 1990, The Eye debuted at number 179 on Billboard 200. However, the band did not tour in support of the album, due to lack of label support. Following The Eye, Hal Patino and Pete Blakk were replaced by Sharlee D'Angelo and Mike Wead respectively. However this line-up ended-up not recording any material, as vocalist King Diamond reunited with Mercyful Fate in 1993 (King Diamond would balance recording and touring with both Mercyful Fate and his eponymous band throughout the 1990s).
After recording and touring with Mercyful Fate, King Diamond reformed his eponymous band in 1994. With the line-up of King Diamond, Andy La Rocque, as well as guitarist Herb Simonsen, bassist Chris Estes and drummer Darrin Anthony from the Texas band Mindstorm, the band spent September through October, 1994, recording their next album. Released on June 6, 1995, The Spider's Lullabye was the band's first album on Metal Blade Records, as well as their first studio release since Fatal Portrait to not be a concept album. The album went on to peak at number 31 on the Finnish album charts. In March 1996, King Diamond began recording their seventh studio album at the Dallas Sound Lab. Released on October 1, 1996, The Graveyard saw King Diamond returning to writing concept albums. The album also charted at number 23 in Finland. After the album's release, drummer Darrin Anthony was forced to leave the band due to a car accident and was subsequently replaced by Chastain drummer John Luke Hebert.
On February 24, 1998, King Diamond released the album Voodoo, which charted at number 27 on the Finnish album chart and at number 55 on the Swedish album chart. After the album's release, guitarist Herb Simonsen was replaced by Glen Drover. When Mercyful Fate was put on hold in 1999, King Diamond began recording the album House of God at the Nomad Recording Studio in Carrollton, Dallas, Texas, with their new bassist Paul David Harbour, who had replaced Chris Estes. Released on June 20, 2000, the album peaked at number 60 in Sweden. After the album's release, guitarist Glen Drover and drummer John Luke Hebert were replaced by Mike Wead and Matt Thompson respectively.
Recent years (2001–present)
King Diamond performing in Kraków
In May 2001, King Diamond began recording their tenth studio album once again at the Nomad Recording Studio. Released on January 29, 2002, Abigail II: The Revenge was a sequel to 1987's Abigail album. It was also the first King Diamond album since 1990's The Eye to feature bassist Hal Patino who rejoined the band during the recording process. King Diamond did not tour in support of Abigail II, as Metal Blade could not provide tour support, due to illegal downloading. Despite this, the album went on to peak at number 24 in Finland and at number 42 in Sweden.
On October 21, 2003, King Diamond released the album The Puppet Master, which charted at number 36 in Sweden. Besides featuring the band, the album also featured additional vocals from Livia Zita, who is also King Diamond's wife. During the supporting tour for The Puppet Master, the band recorded the live album Deadly Lullabyes, which was released September 21, 2004. In April 2006, former bandmate Mikkey Dee (currently with Scorpions, formerly with Motörhead) made a guest appearance at King Diamond's sold-out gig in Gothenburg, Sweden. On June 26, 2007, King Diamond released the album Give Me Your Soul...Please. The album went on to peak at number 25 on the Finnish chart, number 28 on the Swedish chart, and at number 174 on the Billboard 200. The track "Never Ending Hill" also garnered a Grammy nomination for "Best Metal Performance" (the group's first). A music video was also made for the album's title track.
In late November 2010, King Diamond was rushed to the hospital after having several heart attacks. There it was discovered that three of his arteries had been blocked, which meant he had to undergo triple bypass surgery. Following a successful operation, he returned home to rest. Diamond also stopped smoking entirely, changed his diet and began getting regular exercise, according to his wife. On January 27, 2012, Diamond made a special appearance at the "5th Annual Nomad Recording Studio Throwdown", performing three songs: "The Family Ghost", "Evil" and "Burn". On June 9, 2012, the entire King Diamond band played at the Sweden Rock Festival. They were also joined on stage by Michael Denner, Hank Shermann, Mickey Dee and Volbeat's Michael Poulsen. According to vocalist King Diamond, the band expects to begin writing new material for their next album in the fall of 2012.
On July 19, 2014, the band announced that Hal Patino has been relieved of his duties, for reasons very similar to why he was fired from the band in 1990. He was replaced by Pontus Egberg, formerly of the bands Lion's Share and the Poodles. In October, King Diamond announced a new compilation titled Dreams of Horror which was released in November through Metal Blade Records, covering the band's entire career. In December, Egberg became an official member of the band.
King Diamond took part in the 2015 Rockstar Energy Mayhem Festival along with bands such as Slayer (who was chosen as the headliner), Hellyeah, The Devil Wears Prada, Thy Art Is Murder, Jungle Rot, Sister Sin, Sworn In, Shattered Sun, Feed Her to the Sharks, Code Orange and Kissing Candice. The tour ran from June 26 through August 2. At the July 8, 2015 show in Milwaukee, Wisconsin, King Diamond was forced to perform without his signature face paint due to a severe eye infection he sustained, in which doctors advised against the use of any makeup. He explained that there was no negative feedback from the fans.
In April 2018, several new projects were announced by King Diamond. Those include: a new studio album, a DVD with two full live concerts from 2015 and 2016, and a tour described as "playing more shows than we might have ever played in a year in our career. And that has a lot to do with new management and a great booking agent and record label"  King Diamond is after many years of not having management represented by
5B Artist Management.