Released in 1989, Conspiracy is the fourth King Diamond album, and is the second part of a story that began on the previous album Them.

In this sequel to Them, an adult King returns to the House of Amon to reclaim his rightful place as heir to the house. However, unanswered questions about his sister's death, his mother's involvement with his diabolical therapist, and his own madness all prove to be difficult if not insurmountable obstacles. Whereas King’s previous band Mercyful Fate was overtly satanic and occult, the King Diamond material was more fantastical and conceptual, though still with dark themes throughout.

When King’s original band Mercyful Fate split up, having released two genre defining masterpieces ‘Melissa’ and ‘Don’t Break the Oath’, he formed King Diamond along with guitarist Michael Denner and and bassist Timi Hansen The line up on Conspiracy was completed by guitar virtuoso Andy La Roque, and drummer Mikkey Dee who left the group after this album, and eventually joined Motorhead.