Berlioz began toying with the idea for his Te Deum as early as 1832 while travelling in Italy. He arrived as some of the locations prominent in Napoleon's triumphant Italian campaign, and wrote in his pocket book the sketch for a programme symphony: “The return of the army from Italy. Symphony in Two Parts. 1. Farewell in the high Alps to the heroes who fell on the Italian fields. 2. The triumphant entry of the victors into Paris.” The Bonaparte symphony was never written, but the first part evolved into the Grande symphonie funčbre et triomphale while the second resurfaced in the Te Deum. The Te Deum was written in 1850 but had to wait until 1855 for its premiere. Maurice Bourges gave the following description of the work (which Berlioz himself endorsed) in the paper %u201CGazette Musicale”: %u201CBerlioz's conceived of the Te Deum as a partly epic, partly dramatic work of collosal dimensions, and was designed to celebrate the military glory of the first consul. Originally, it would have comprised of a single episode, with the title %u201CReturn from the Italian campaign.” Berlioz conceived the hour when Napoleon's generals enter under the immense vault of the cathedreal, while the holy hymn quietens down, the flags flutter, the drums beat, and the cannons roar, and the bells peal in a dignified fashion. This explains its composition's mood which is reminiscent of a military parade.”

The Te Deum was first performed in the Saint-Eustache cathedral on the occasion of the opening of the Industrial exhibition. Berlioz himself conducted. The immense forces Berlioz required in addition to its sheer visual spectacle as it was performed before an audience numbered in the thousands, boosted its visceral impact. Berlioz planned precisely where the participants in this ritual were to be stationed. The 160 strong orchestra and the choirs with 100 members each were placed as far away as possible away from the organ. Nearby on a separate terrace stood a 600 strong children's choir. And the organ itself is heard echoing from the other end of the cathedral.