In an email, Peter Carter, a partner at Finers Stephens Innocent, confirmed that G&I Holst Ltd. and music publisher G. Schirmer Ltd. issued proceedings in the High Court in London on April 12, 2006, alleging that part of Zimmer's Gladiator soundtrack infringes copyright on the opening movement of The Planets, "Mars, the Bringer of War."
The proceedings are against Hans Zimmer's publishers and various Universal entities involved in the distribution of the film and the CD soundtrack.
Composed around 1915, The Planets includes a movement for each of the seven planets (excluding Earth) that were known at the time. Holst wrote music to reflect the characters of the Roman gods after which the planets were named. "Mars, the Bringer of War" is a brashly martial piece with lots of brass and percussion. John Williams's score for Star Wars, to name one example, also evokes Holst's "Mars."
Zimmer, a veteran film composer, most recently wrote the score for The Da Vinci Code. His credits also include The Thin Red Line, Batman Begins and Backdraft.