ENOriginally the patronage of the sovereign of the Polish-Lithuanian Commonwealth made the basis for the establishment of the Lithuanian Catholic Church. Later the nobility also participated in the process of the consolidation of the Church. In accordance with the patronage right the sovereigns appointed church officials to the newly established parishes and the diocesan chapters of Vilnius and Samogilia. This article is based on the data of 229 privileges found in the books nos. 123-149 of the Lithuanian Metrica. They contain 164 full texts of such privileges, while others are mentioned only in the register. The privileges are not a very informative source, since they are recorded according to a standard formula. The sovereign had a patronage right in 84 parishes of Vilnius diocese, in 14 of Samogitia, in 3 of Smolensk, in 2 of Livonia and in 8 of Lutsk - that made up ca. 30 percent of all the parishes. He also appointed deans to the richest and most important parishes of Raseiniai, Šiauliai, Kražiai, Geranainys, Anykščiai, Ramygala, Slonimas, and Trakai. The privileges provide the researcher with some information about 309 church officials in the latter half of the seventeenth century. The appointments show the ruler’s concern with the qualities of appointees, their level of education, origin, morality, loyalty to the Church and the state. Their educational background was quite sufficient, as a rule they had received full ordination as priests. The canons and other high officials had studied at the universities of Vilnius, Cracow or in Italy, and twelve of them had doctor’s degrees. The command of Lithuanian and noble origin were preferred. None was allowed to have more than one parish.Enjoying royal patronage church officials could expect greater success in their careers in state offices. According to this study, the largest group of church officials (16 persons) were royal secretaries. Other popular occupations were those of spiritual referendaries (eight) and spiritual secretaries (four) - these posts could be held only by ecclesiastical people. Church officials were heads of chanceries and treasury clerks - usually their careers began from these posts. The canons of the diocese of Vilnius (the biggest in the GDL) and other members of its chapter were also influential in the government of the state. [From the publication]