Immortal Imperium comes from the official soundtrack to Warhammer 40,000: Darktide, the cooperative action game released in 2022 and set in the grim Warhammer 40,000 universe. The track captures the Imperium's fanatical, cathedral-scale atmosphere, which is why fans lifted the chant for their own videos long after the game's launch. It spread through Warhammer edits, lore videos and gaming montages on social platforms, where its solemn choir instantly signals the Imperium. That instant recognition keeps it popular for dramatic, dark science-fiction content.