The phrase comes from Warhammer 40,000, the tabletop setting created by Games Workshop in 1987, where the Imperium of Man is a vast, fanatical human empire devoted to the Emperor. In French, Pour la gloire de l'Imperium functions as a loyalist battle cry for Space Marines and Imperial troops. Francophone fans and gaming creators spread the shouted version online as a short reaction clip, using it far beyond tabletop matches to announce attacks, victories and proudly exaggerated declarations of loyalty in edits and streams.