This paper introduces unknown manuscripts to researchers, which contain records of a philosophical course (1691/2–1692/3) and theological courses (1693/4–1696/7) taught in Kyiv-Mohyla College by Stephan Jaworsky. The manuscripts are kept in the National Library of the Russian Federation in Saint-Petersburg. It has been found out that these records were made by a student Basil Holenkowsky by name, who ended his life under the name of Barlaam as an Archimandrite of the monastery on Kiy-island in Onega lake in 1722. (...) The study of his biography allows to clear up some codicological features of the manuscripts when and where they were bound and the history of the manuscripts when and how they got into the National Library of the Russian Federation. A new analysis of sources, even of those already known to historians, also may support an interpretation of facts of life of this person and his acts not only within the framework of the traditional historiography of the 19th century, but also as a concsious choice of a person who followed pragmatic considerations. On the other hand, the brought to light manuscripts allow not only to argue when Holenkowsky attended the Kyiv College but also to assume hypothetically when he could enter the college, who were his fellow-students, and how that could have affected his future. The manuscripts from Petersburg contain signs of the dates and authorship of these courses inside, which are not found in other known records. If one compares these manuscripts with other records of these courses, they can note that the record of the philosophy course is complete, while the one of theology doesn’t contain some parts of the course taught during the forth year. That can be interpreted as a sign of Holenkowsky’s not having attended the forth year of this course. (shrink)