CAELENAE. — It is beyond doubt that in the land of the Marsi there existed a sufficiently ancient Christian church. In the 6th century explicit mention is made of a bishop named Giovanni of the Marsi. For now, however, it is impossible to establish its origins, since the legendary tradition of St Rufinus, the first bishop of the Marsi in the 3rd century (BHL, 7360-63), is not worthy of credence.
It may be supposed that the first episcopal see was Marruvium (today S. Benedetto), the chief town of the Marsica, and at a later time probably C. (Celano). From the 10th century certain records allow us to follow its history, which was later illustrated by the bishop St Bernard, cardinal of the title of S. Crisogono. After the ancient city was destroyed, the cathedral church of S. Sabina remained, to which the Roman pontiffs, as metropolitans, repeatedly confirmed its possessions and rights in the subject territory, until Gregory XIII transferred the episcopal see to Pescina in 1580. At present the residence is at Avezzano (v. dei).
Of the numerous collegiate churches and abbeys, which abundant documents suggest were once flourishing, as at Celano and Trasacco and subject to the bishop of the Marsi, very little remains. Notable is the abbey of S. Cosma at Tagliacozzo, of which the temple still stands.
At Pescina the episcopal and chapter archives contain few documents because of the dispersal that occurred prior to the transfer of 1580.