An abode in Florence was nevertheless ill suited to the new course of life which he proposed to himself. The city was perpetually disturbed by domestic strife, or the treachery of the foreign princes, whom they called in to their assistance in time of war. Boccaccio retreated from this scene of discord, and took up his abode at the castle of Certaldo, where he gave himself entirely up to study: his house there is still to be seen. Certaldo is situated on a hill, and looks down on the fertile valley watered by the river Elsa.[75] The country around is picturesque, adorned by various castles and rustic villages. The culture of corn, vines, and olives, adorns the depth of the valley and the uplands; and three successive harvests are brought in by the husbandman. Here Boccaccio composed most of his later works, and the influence of Petrarch is perceptible in his choice of subjects and language. This is to be greatly lamented, since his desertion of Italian was founded upon a mistake, which has given us, instead of works of imagination and genius, heavy treatises and inaccurate histories. Boccaccio's Latin is bald and tame; he knew nothing of the structure, and was unable to clothe his thoughts with the eloquence natural to him: he rattled the dry bones of the skeleton of a dead language, instead of making use of the young and vigorous tongue to which he had given birth. His first work, under this new direction, was one of great labour and erudition for those times, and was entered upon at the suggestion of Ugo IV., king of Cyprus and Jerusalem. It treats of the genealogy of the gods, and relates the connection between the various deities of the beautiful Greek mythology. For many years it continued to be a standard book, whence the Italians drew all their knowledge of the subject; and it was doubtless a useful production. In pursuance of his plan of being the schoolmaster of his age, and introducing his countrymen to the knowledge of forgotten lore, he afterwards composed a dictionary of ancient rivers, mountains, and forests. His active mind was always finding new subjects for his pen. He discovered that the female sex possessed no historian, and he dedicated himself to their service by writing the lives of illustrious women. In this he describes the ideal of a virtuous matron, and goes to the extreme usual to a reformed libertine. Her conduct must not only be strictly correct, but she must not even look about her; she must speak little, eat little, and avoid singing and dancing. Given up to domestic cares, she must be simple in her dress, and even love her husband moderately. He wrote after this a work entitled, "De Casibus Virorum et Fæminarum Illustrium," in which he records the disasters and adversity which history relates to have befallen royal or noble personages. Thus his time was entirely spent among his books, and he acquired a reputation for learning and purity of life, which raised him high in the opinion of his fellow citizens.