ENThe article presents the history of icon worship in the Unitarian Orthodox church in the Radziwiłł-owned village of Nowy Świerżeń (present-day Novy Sverzhen) in the 17th–18th centuries. The history of the worship is analysed in the context of the influence on its development of the representatives of the Radziwiłł family. In order to animate the cult and provide pastoral care to arriving pilgrims, like at the Marian worship site in Żyrowice, Prince Aleksander Ludwik Radziwiłł planned to bring the Basilian Order to the village in 1652. The foundation was finalised as late as 1740. Many pilgrims came to Świerżeń to experience miraculous healings. As a token of gratitude, they placed votive offerings next to the icon. Reports of miracles were recorded in Księga Cudów (The Book of Miracles), the first edition of which was published in 1650, and a second edition, supplemented with information on more miracles, in 1750. The Marian devotion centre in Nowy Świerżeń remained an important place of worship for the local community in the modern era. It has not received more than local publicity, the in the Świerżeń Orthodox Church was initiated at a time when many other places of Marian devotion had a long tradition, and others had already gained fame. This condition was also influenced by the Radziwiłłs’ insufficient support for the promotion of the cult of the Virgin Mary in the image in Nowy Świerżeń. Keywords: Uniate Church; Lithuanian province of the Basilians; Marian devotion; religious culture; Grand Duchy of Lithuania; Basilians; Radziwiłłs; Novy Sverzhen.