When We Are Gathered is the first Marduk album to feature Legion, formerly of Ophthalamia, on vocals and Peter Tägtgren as mixer.

This album marked a shift in style for what Marduk are popularly known for; hyper-blast blast beats and furious drum work, sheer brutality over melody (compared to previous releases), and raw vocals.

[3] The music for "Glorification of the Black God" is an adaptation of Modest Mussorgsky's "Night on Bald Mountain".

Furthermore, the lyrics of the song are clearly inspired by "Bald Mountain's" basic theme (a witches' Sabbath on St. John's Night).

[citation needed] The title of the album is a reference to the Bathory song "Dies Irae" from Blood Fire Death.