The 4th century is a period of religious tolerance in the Roman Empire. It is a period of religious transition between the last persecutions of Christians at the start of the century and the institutionalisation of Christianity as sole state religion by emperor Theodosius I. at the end of the century.

Four soldiers of the 14th legion stationed at Carnuntum on the Danube frontier, walk through the marsch lands of the Danube in order to find the local bishop and to bring him to a private house for a private mass. The first large churches are being built since the start of the 4th century, but in most border towns, services are still held in private houses and even hidden places at times. Christianity is not very present in Carnuntum yet. Absence of much Christian findings in the archaeological record indicate that Carnuntum still had a strong pagan community in the 4th century. This is shown by the absence during the mass of two of the soldiers initially among the party, as they still adhere to the older cults.

Music: Roman Chant (6th century AD).
Title: "Introitus: Dominus dixit ad me".
Service: Mesonycticon (Midnight Mass).
Performers: Ensemble Organum, Director: Marcel Peres
Album: "Chant de l'Eglise de Rome (VIe XIIIe Siècles)"