The article explores the relationship between the patronage of monasteries and territory control in Greater Armenia in the second half of the 9^th century based on the study of three cases. The first is the foundation of the Monastery of Sevan by Princess Mariam Bagratid and the renowned ascetic Maštoc‘ in 871. It is suggested that this and other monastic foundations around Lake Sevan (Gełark‘unik‘ territory) were a means of extending Bagratid influence, if not yet full control, on this neighboring region ruled by the Siwnids.