Born in Ancarano, in the modern Abruzzo region, he devoted himself to the study of mathematics and astrology. In 1322 he was made professor of astrology at the University of Bologna. It is alleged that he entered the service of Pope John XXII at Avignon, and that he cultivated the acquaintance of Dante only to quarrel with the great poet afterwards; but of this there is no evidence.
Having published a commentary on the sphere of John de Sacrobosco, in which he propounded audacious theories concerning the employment and agency of demons, he got into difficulties with the clerical party, and was condemned in 1324 to certain fasts and prayers, and to the payment of a fine of seventy crowns. To elude this sentence he went to Florence, where he was attached to the household of Carlo di Calabria. His freethinking and plain speaking had made him many enemies; he had attacked the Commedia of Dante, and the Canzone d'amore of Guido Cavalcanti; and his fate was sealed. the physician Dino del Garbo was indefatigable in pursuit of him; and the old accusation of impiety being renewed, Cecco was again tried and sentenced, this time to the stake. He was burned at Florence the day after sentence, in his seventieth year.
Cecco d'Ascoli left many works in manuscript, most of which have never been given to the world. The book by which he achieved his renown and which led to his death was the Acerba (from acervus), an encyclopaedic poem, of which in 1546, the date of the last reprint, more than twenty editions had been issued. It is unfinished, and consists of four books in sesta rima. The first book treats of astronomy and meteorology; the second of stellar influences, of physiognomy, and of the vices and virtues; the third of minerals and of the love of animals; while the fourth propounds and solves a number of moral and physical problems. Of a fifth book, on theology, the initial chapter alone was completed.
A man of immense erudition and of great and varied abilities, Cecco, whose knowledge was based on experiment and observation (a fact that of itself is enough to distinguish him from the crowd of savants of that age) had outstripped his contemporaries in many things. He knew of metallic aerolites and shooting stars; the mystery of the dew was plain to him; fossil plants were accounted for by him through terrain revolutions which had resulted in the formation of mountains; he is even said to have divined the circulation of the blood. He may be described as one of the Cassandras of the Middle Ages: a prophet who spoke of coming light, but was accused of impiety.
The least faulty of the many editions of the Acerba is that of Venice, dated 1510. The earliest known, which has become excessively rare, is that of Brescia, which has no date, but is ascribed to ca. 1473.