Introduction – I. Etymology and meaning – II. First and second centuries – III. Third century – IV. Fourth and fifth centuries – V. Sixth century – VI. Seventh century. Introduction. We will confine ourselves to elementary oral religious instruction, especially as it was imparted during initiation into a worshiping community. The recipients are, in the first place, the initiates themselves andor the parents, their sponsors R. Turcan, Initiation: RAC 18, 87-159; P.-M. Gy, La notion chrtienne d’initiation, in Id., La liturgie dans l’histoire, Paris 1990, 17-39. Initially elementary instruction coincided with the missionary message the kerygma and was not strictly distinguishable from it see, e.g., Acts 8:12; 18:8. In its later development it became baptismal instruction on faith, on the conduct of one’s life and on the sacraments of initiation prima fidei rudimenta: Hilar. Arel., vit. Honorat. 5 SC 235, 82; this was divided into: 1 the catechumenate M. Metzger et al., Katechumenat: RAC 20 2003 497-574 and postbaptismal mystagogy see Cyril of Jer., Cat. 18,33; 2 preparation of parents and godparents for the baptism of babies; and 3 the ongoing daily element of catechesis in the Late Antique and Early Medieval liturgy of communities and monasteries. Catechesis thus understood is distinguished from normal education and scholarly formation enkyklios paideia; within Christianity it is distinguished by its purpose and not necessarily by its form and name from ordinary Sunday, daily and festal homilies M. Sachot, Homilie: RAC 16, 155-175, though candidates for baptism were usually among the hearers of these latter homilies. At the same time, baptized persons also listened to catechesis and to mixed forms of catechesis and homily. We will not address here the teaching given to Christian officeholders or catechesis within monasticism.