The priests of the Croatian cultural space utilised not only Latin and Church Slavonic as liturgical languages, but also a literary language that had been formed in accordance with the spoken language of the common people. This liturgical language originated in the shadow and on the basis of Church Slavonic, and was used by Croats in Roman Catholic worship for centuries prior to the Second Vatican Council (1962). The language spread partly due to the legend of St. Jerome, who was said to have translated the Holy Scripture into the language spoken by the Dalmatian Slavs, i.e., Croats, and had written it down in Glagolitic script, the primary Croatian Glagolitic alphabet. The legend of St. Jerome also influenced the creation of the first printed Croatian dictionary by Faust Vrančić (Faustus Verantius). It classifies the “Dalmatian” language among the noblest of the European languages, primarily due to the assumption that it was St. Jerome’s mother tongue. This marks the origin of Croatian lexicography at a time when the first Croatian grammar was composed by a Jesuit, Bartol Kašić (Bartholomaeus Cassius), who, acting on the order of the Catholic Church, had created the grammar to be used for the purposes of missionary work. These facts demonstrate that the development of Croatian literary language at its earlier stages, was aligned with the strivings and needs of the Catholic Church and that Croatian liturgical language of the Catholic Church had made a crucial impact and directed the development and emergence of Croatian literary language.