Catalogues of martyrs and saints arranged according to the occurrence of their feast days in the calendar. Originally the martyrologies were local lists of martyrs of some section or city. Later the names of holy bishops were added, then the names of other than local martyrs and bishops, and finally the names of saintly confessors. Martyrologies originated in the early ages of the Church, hence they are an important source for history. The most celebrated of the ancient martyrologies is the Hieronymian. It was probably written sometime in the 5th century from various local and sectional martyrologies. In some ancient martyrologies a short history of the saint follows his name. The present Roman Martyrology, the catalogue of the saints honoured by the Church, first appeared in 1584, and has been revised and edited several times since. In religious communities and seminaries it is read out each day at the principal meal; where the Office is chanted in choir, it is sung during Prime. Each daily list consists of about 15 names of saints of all types, martyrs, confessors, bishops, virgins, etc; usually the saint whose Mass is said on the particular day heads the list.