**LEO OF VERCELLI** – Lived between the 10th and 11th centuries. He is first encountered at the court of Emperor Otto III. His birthplace and how he came to the court are unknown. The first reliable account shows him in September 996 among the courtiers in Mainz, where he distinguished himself for his eloquence and explained a prophetic dream to Adalbert of Prague, foretelling his martyrdom (Brunonis vita Adalberti, 20, in MGH, Scriptores, XV, p. 605). In 997, he met the great scholar Gerbert of Reims, from whose influence he drew inspiration for his ideas on the universal dominion of the Empire; familiar with both the Emperor and Gerbert, he worked in the autumn of 997 toward this end (Lettres de Gerbert, 183, ed. J. Havet, Paris 1869, p. 168). The Emperor’s trusted man was elected Bishop of Vercelli, where the Empire needed energetic and loyal support against the violent attacks of Margrave Arduino of Ivrea. The title of *episcopus palatii*, found in the life of Adalbert written in 1004 by Bruno of Querfurt, is merely an epithet he received due to his frequent residence at court and his interest in imperial affairs.
It is not known when he took possession of his see. According to Canetti (Della serie cronologica dei vescovi di Vercelli, Vercelli 1886, p. 24 sqq.), Leo could have become Adalbert’s successor no earlier than the summer of 998. In the spring of the same year, Leo was in the retinue of the Emperor and Pope Gregory V in Rome, taking an active part in the council where the antipope John Philagathus was deposed. On that occasion, he composed a poem dedicated to Pope Gregory V, celebrating his return and praising the shared universal dominion of Emperor and Pontiff.
In Vercelli, Leo restored order; he worked to ensure that Arduino accounted for his anti-imperial policies at the Roman Synod of 999. The title of *logothete* that Leo uses in the subscriptions of two *placita* from 1001 seems to indicate that at that time he held the position of chancellor, in place of Heribert, who had been promoted to the archiepiscopal see of Cologne. The most precious monument preserved of Leo’s activity is the diploma by which Otto III granted the Church of Rome eight counties, thus concluding peace with the Pontiff. According to this authentic document, drafted by Leo himself, and other capitularies and diplomas, he appears as a trusted advisor of the Emperor and a supporter of his policies for the Church of Rome.
An intimate friend of Emperor Otto III, Leo shared his ideas on Empire and universal supremacy. He did not, however, share his mysticism; indeed, he is portrayed as overly preoccupied with worldly affairs (MGH, Scriptores, XV, p. 725). At Otto’s death, which he sincerely mourned, he worked to persuade Otto’s successor, Henry II of Bavaria, to descend into Italy against Arduino. From his letters and other accounts, it emerges that Leo was effectively the guiding spirit of the pro-imperial faction in northern Italy.
In the following years, Leo devoted himself to organizing the affairs of his diocese, though he soon found occasion to take part in imperial affairs again. He played an important role in the Synod of Pavia in 1022, convened by Emperor Henry II and Pope Benedict VIII. He was the author of the canons of Pavia, which he immediately sought to implement in his diocese. At Easter 1026, he received King Conrad II in Vercelli during his journey to Rome. A few days later, he died. His significance lies in having, as Bishop of Vercelli, supported the German dominion in Lombardy for nearly three decades with success. He signed himself *episcopus Imperii*. This conception of the episcopal office and authority also underpinned his opposition to the Cluniac reformers, William of Dijon, and Rodulfus Glaber, who saw their adversary in this courtly, presumptuous, and overbearing bishop. While the monks of the reform found him too worldly, the supporters of the emperors, such as Benzo of Alba, exalted him as a champion of past imperial glory.
**LEONI, LEONE** – Medal with a portrait of Michelangelo at age 88; on the reverse, an allegorical representation alluding to Faith, conceived by Michelangelo himself – Florence, Medicean Medagliere, Bargello.