CIACONIO (ChAcón), Pedro. - Spanish theologian and humanist, b. in Toledo in 1527, d. in 1581 in Rome, where he resided for a long time. He was entrusted by Gregory XIII with the task of revising the text of the Bible, of many sacred writers, and of the Decretum Gratiani. He collaborated on the reform of the calendar. He annotated the works of Arnobius, Minucius Felix, and Tertullian.
BIBL.: Biografia ecclesiastica completa, III (1820), pp. 791 ff. (with portrait); Hurter, III, cols. 278-81; E. Freys, s. V. in LThK, II, col. 821; Anon., s. V. ENOCH. Eur. Am., XVI, cols. 1378 ff.