The establishment of a collection of Orthodox church art in Lancut was dictated by the need to protect priceless cultural property threatened by the displacement of the Ukrainian population from the area of southeastern Poland in 1945 and 1947. The decades-long period of deliberate destruction of monuments of religious art led to the destruction of some 330 Orthodox churches out of the 650 that existed in that part of the historic Przemyśl diocese, which after World War II became part of the Polish state. The multiplication of losses was prevented by a campaign led by museum workers to secure "unwanted mementos of history," mainly paintings, book collections and artistic crafts.

The establishment (in 1960) of the Provincial Repository of Movable Antiquities in Łańcut, later transformed into the Department of Orthodox Art of the Łańcut Castle Museum, is part of these activities. Equipment of many unattended Orthodox churches was systematically brought to it.

Initially in hastily prepared storerooms, later in a specially adapted wing of the building of the former cug stables, more than 1,000 icons (15th-20th centuries), handicrafts and a 300-volume collection of old Cyrillic prints found a home, the highlight of which is a meticulously restored Apostle from the Lviv Fedorov printing house from 1574. Today it is the largest collection of Ukrainian sacred art in Poland. The collection is under constant conservator's care, enriched through museum purchases and opened to the public. Some of the church furnishings have returned to their original places after years and are used for worship..