It is also known as the «Soldiers' church» It was build by Jules Hadouin-Mansart, who was inspired by Libéral Bruant's drawings (prior to the Dome being built). It is a severe and stark building and the only decoration used are the flags taken from the enemy, that are hung from the cornices. The organ, a magnificent 17C instrument, played Berlioz's famous Requiem for the first time in 1837.