The family of the Cybo was of very ancient, perhaps of, Byzantine origin. They possessed in the tenth century islands and walled towns. In 1188, Ermes Cybo subscribed the treaty of peace between the Pisans and Ligurians. We find in old manuscripts that, in 1261, they had palaces in the via del Campo. A Guglielmo Cybo, who died in 1311, built the magnificent church of St. Francis in Casteletto and there was erected the marble sepulchre of himself and his family. This Guglielmo rendered important services to the Republic for which he obtained the privilege of adding to his arms the device of the Republic.[49] The family produced many other distinguished men, among whom may be mentioned Innocent VIII. In his youth, this pontiff became the father of a son named Francesco who was governor of Rome during the pontificate of Innocent and married Maddalena de’ Medici sister of Leo X. In the year 1500, Lorenzo Cybo was born of this marriage in St. Pierdarena, a suburb of Genoa. Lorenzo devoted himself to arms, and in the Milan war, carried the fortress of Monza by assault. The cardinal Innocent Cybo, his elder brother, ceded him the county of Ferentillo and he also governed Vetralla, Giano and Montegiove. Desirous of enlarging his estates, he married Ricciarda daughter and heiress of Alberico Malaspina, Marquis of Massa and Carrara and widow of Count Scipione Fieschi who died in 1520. Ricciarda bore Lorenzo several children, one of whom was Eleonora wife of Gianluigi Fieschi. There were besides, Isabella, who married Vitaliano Visconti Borromeo, Giulio and Alberico. Giulio, whose career we shall briefly recount, was born in Rome in 1525, and was educated in the court of Charles V. where the beauty of his person and the sprightliness of his intellect acquired him the admiration of the Spanish courtiers.