The remains of St. Mary’s church on the Veliki Brijun Island, part of the Brijuni Island National Park off the western coast of the Istrian peninsula. The aisled church of square ground plan has lateral walls preserved almost to their original height. The size of the church (11x 24 m) indicates a large population in the 5th – 6th centuries.
The beginning of the 9th century saw the renovation of numerous churches, among them St. Mary’s. It was refurbished with new stone furnishing bearing the recognizable interlace pattern. The large pagan population must have caused missionary activities carried out by the Benedictines from the many monasteries. If not earlier, this is when the Benedictine monastery was founded stretching north and south of the church.
In the 13th century the basilica belonged to the Templars, but when their order was abolished in 1312, life in the monastery faded away.