JOACHIM OF FLORIS (c. 1145-1202), so named from the monastery of San Giovanni in Fiore, of which he was abbot, Italian mystic theologian, was born at Celico, near Cosenza, in Calabria. He was of noble birth and was brought up at the court of Duke Roger of Apulia. At an early age he went to visit the holy places. After seeing his comrades decimated by the plague at Constantinople he resolved to change his mode of life, and, on his return to Italy, after a rigorous pilgrimage and a period of ascetic retreat, became a monk in the Cistercian abbey of Casamari. In August 1177 we know that he was abbot of the monastery of Corazzo, near Martirano. In 1183 he went to the court of Pope Lucius III. at Veroli, and in 1185 visited Urban III. at Verona. There is extant a letter of Pope Clement III., dated the 8th of June 1188, in which Clement alludes to two of Joachim's works, the _Concordia_ and the _Expositio in Apocalypsin_, and urges him to continue them. Joachim, however, was unable to continue his abbatial functions in the midst of his labours in prophetic exegesis, and, moreover, his asceticism accommodated itself but ill with the somewhat lax discipline of Corazzo. He accordingly retired into the solitudes of Pietralata, and subsequently founded with some companions under a rule of his own creation the abbey of San Giovanni in Fiore, on Monte Nero, in the _massif_ of La Sila. The pope and the emperor befriended this foundation; Frederick II. and his wife Constance made important donations to it, and promoted the spread of offshoots of the parent house; while Innocent III., on the 21st of January 1204, approved the "ordo Florensis" and the "institutio" which its founder had bestowed upon it. Joachim died in 1202, probably on the 20th of March. Of the many prophetic and polemical works that were attributed to Joachim in the 13th and following centuries, only those enumerated in his will can be regarded as absolutely authentic. These are the _Concordia novi et veteris Testamenti_ (first printed at Venice in 1519), the _Expositio in Apocalypsin_ (Venice, 1527), the _Psalterium decem chordarum_ (Venice, 1527), together with some "libelli" against the Jews or the adversaries of the Christian faith. It is very probable that these "libelli" are the writings entitled _Concordia Evangeliorum_, _Contra Judaeos_, _De articulis fidei_, _Confessio fidei_ and _De unitate Trinitatis_. The last is perhaps the work which was condemned by the Lateran council in 1215 as containing an erroneous criticism of the Trinitarian theory of Peter Lombard. This council, though condemning the book, refrained from condemning the author, and approved the order of Floris. Nevertheless, the monks continued to be subjected to insults as followers of a heretic, until they obtained from Honorius III. in 1220 a bull formally recognizing Joachim as orthodox and forbidding anyone to injure his disciples.