ENThe Basilian Order exerted a powerful influence on the image of the Uniate Church during its entire existence in the lands of the Grand Duchy of Lithuania. The Order controlled the spiritual and public education, pilgrim places, owned wonderful paintings and supervised the publishing activity. The Order shaped religious awareness, piety, the cultural face of the Uniate community. At die same time, the Order did not become an authentic heir to the spiritual and monastic traditions of Eastern Christianity, it was not a culture-creating factor for the Uniate Church. The basic internal contradiction of the Basilian order was the necessity of existence in the Eastern external tradition, which the Order consistently filled with Latin content. That led to a drastic Latinization of the Uniate tradition and resulted in the fall of the latter, which also marked the collapse of the Lithuanian provincial monastery in the nineteenth century during the church reforms of Józef Siemaszko. Keywords: Basilian Order, Uniate Church, The Grand Duchy of Lithuania. [From the publication]