St. Brendan was an Irish monk of the fifth and sixth centuries who made extensive sea journeys to spread the Gospel to the islands around Ireland and to found monasteries. His most famous adventures are recounted in the Voyage of St. Brendan. According to the Voyage, St. Brendan and his monks celebrated Mass on several occasions on an island that was really the back of the largest fish in the ocean, which is named Iasconius.
the borders are in the style of 6-9th century Northumbro-Irish art, with its distinctive ornamental knotwork, lacertine animals and geometric patterns.