In Paris, in 1550, when the printing press was still relatively new, Gervais de Tournay published a medieval chronicle under the title, Historia Hugonis Falcandi Siculi De rebus gestis in Siciliae regno iam primum typis excusa [« The History of Hugo Falcandus the Sicilian, concerning things done in the Kingdom of Sicily, now printed for the first time »]. He had discovered this history, as he explains in his preface, in a codex placed at his disposal by Matthew Longuejoue, bishop of Soissons, a codex so ravaged by time that it looked repulsive enough to poison the hand that dared to touch it. But he was pleased to save from oblivion the admirable work contained within it. Apparently the Historia evoked this reaction through its literary qualities alone, since Gervais seemed to know nothing about the time or place it concerned, and in his preface, he made, as G. B. Siragusa said, a sorry mess (« una brutta confusione ») of the various dynasties which had ruled Sicily. Evidently all the information he gave about the Historia itself, to the extent that it was accurate, came from the codex he had before him, which is now lost. As published, his editio princeps began with a prefatory letter, titled « Letter to Peter, treasurer of the church of Palermo, concerning the calamity of Sicily » (Praefatio ad Petrum Panormitanae Ecclesiae Thesaurarium de calamitate Siciliae) and was followed by the history proper, which was titled De Tyrannide Siculorum. Gervais de Toumay did not know the dates of the events within the Historia, but later scholars supplied them. In fact, the Historia concerns the reigns of the two kings William of Sicily, father and son. It covers the entire reign of William I (r. 1152-1166) who is commonly known as « William the Bad » largely because of the account of him given in this very work, and it continues through the first three years of the minority of William II (r. 1166-1189), commonly called « William the Good » because of his excellent reputation elsewhere. The chronological account of the Historia ends shortly after the great earthquake of February 4, 1169. However, the ostensibly prefatory Epistola ad Petrum, from internal evidence, was written during the political crisis which followed the death of William II in 1189. At that time, a Sicilian faction rejected William's designated successor, Constance, and crowned Tancred, an illegitimate grandson of Roger II, as their king, an act which rendered inevitable the calamitas of the title: the invasion of Sicily by the mighty armies of Constance's husband, Henry VI of Hohenstaufen.
Hood, Gwenyth E. “Falcandus and Fulcaudus, Epistola ad Petrum, Liber de Regno Sicilie: Literary Form and Author’s Identity.” Studi Medievali, June 1999 3rd Series, XL pp. 1-41.