CISSA. – This small city of Istria, situated on an island a short distance from the present-day city of Rovinj, was the site of a purple-dye workshop subject to imperial monopoly. It appears as an episcopal see at the end of the 6th century during the Three Chapters schism; it disappears after the end of the 7th century, though the exact date is unknown, following a seismic event in which the city itself was swallowed by the sea.
BIBL.: F. Babudri, Il vescovado di C. in Istria, in Memorie della Società istriana di archeologia, ecc., 31 (1919), pp. 35 ff. Pio Paschini