This study surveys the musical notation appearing in the liturgical manuscripts of the Order of St. Paul the First Hermit from the fourteenth until the eighteenth century. As a Hungarian foundation, the Pauline Order adopted one of the most elaborate and proportionate Gregorian chant notations of the medieval Catholic Church, the mature calligraphic Hungarian/Esztergom style, and used it faithfully, but in a special eremitical way in its liturgical manuscripts over an exceptionally long period, far beyond the Middle Ages. The research sought to study all the Pauline liturgical codices and codex fragments in which this Esztergom-Pauline notation emerges, then record the single neume shapes and supplementary signs of each source in a database. Systematic comparison has produced many results. On the one hand, it revealed the chronological developments of the Pauline notation over about four centuries. On the other hand, it has been possible to differentiate notation variants, to separate a rounded-flexible and a later more angular, standardized Pauline writing form based on the sources, thereby grasping the transition to Gothic penmanship at the turn of the fifteenth and sixteenth centuries. A further result of the study is the discovery of some retrospective Pauline notation types connected to the Early Modern and Baroque period, after the Tridentine Council. The characteristics of the notations of the choir books in the Croatian and the Hungarian Pauline provinces have been well defined and some individual subtypes distinguished – e.g. a writing variant of the centre of the Croatian Pauline province, Lepoglava.