JOHN XVI, ANTIPOPE. — Born at Rossano in Calabria, died in 1013 (?). J. Philagathos, a Greek of obscure family who, with the favor of the Empress Theophano, became abbot of Nonantola, coadjutor and then bishop of Pavia, and envoy of Otto III to Constantinople, was, upon his return from this legation and in the Emperor’s absence, raised to the papal see, perhaps against his will, by John Crescentius, in opposition to the fugitive imperial pope Gregory V (April 997). When the Emperor returned, J. was blinded, horribly mutilated, and consigned to a monastery. He died, it seems, in the abbey of Fulda.
Enciclopedia Cattolica