This is the Acts of Martyrs in the form of an epistula (“letter”; Epistle) written by the Churches of Lyons and Vienne, and it was sent to the sister communities of Asia and Frygia in order to inform them about the events of the year 177 CE, that is to say, the martyrdom suffered by the Christians of Gaul on that date and of which the victim was a very numerous group of individuals from those two cities.