During the course of history, in various ways and measures, the pastoral structures of the Church and their canonical regulation have taken into account the geographical origin and the language of the faithful. The ninth constitution of the fourth Lateran Council, which was celebrated during the papacy of Innocent III, represents a turning point, in which the whole issue of the pastoral care of the faithful who belong to another rite or language was faced. This essay aims to find the meaning and the effects of the Lateran Constitution, as well as the successive development of the discipline about the language of the faithful (seen as a criterion of ecclesiastical organization), especially in reference to parishes. 


Keywords: Fourth Lateran Council; Innocent III; Pastoral care; language; rite.