The Piccolomini Library is a monumental environment of the Siena cathedral.The library is magically beautiful. Its frescoes and exposed books are priceless treasure. In the honor the memory of the maternal uncle Enea Silvio Piccolomini (Pope Pius II), and to preserve the rich bibliographic patrimony that the pontiff and humanist collected when he was in Rome, Cardinal Francesco Todeschini Piccolomini, archbishop of Siena (later Pope Pius III), around in 1492 he was built a library on the premises of the old rectory along the north-western side of the Cathedral. Todeschini was inspired by the French tradition that included libraries attached to cathedrals and by the opening of the Vatican Library of Pope Sixtus IV. As for the chronology of the frescoes that decorate the library, they were made by Pinturicchio and his workshop in a period of time ranging from 1503 to 1508 and celebrate the life and deeds of the pontificate of Pius II, rich in evocation of landscapes and real and imaginative costumes, with refined representations of ceremonies and characters, performed with a wealth of glazed colors. Among the beautiful murals besides Pope Pius II is the character of Pinturicchio himself. In the scene with the canonization of Saint Catherine of Siena, among the public of the religious orders, in the lower left, the two figures in which the young Raphael (with red stockings) have long recognized themselves, who would have collaborated with Bernardino di Betto the execution of the frescoes in the Library, and Pinturicchio himself (with the red cap). The fifth scene of the cycle is one of the best known: it represents the meeting, promoted by the pontiff, between Emperor Frederick III and Eleonora of Portugal, which took place on February 24, 1452, near Porta Camollia. In addition to the murals in the room, we can also admire the marble sculpture of Three Graces. Magnificent codes ( Hand Painted and Written Books),(Gradualie Antifonari) are preserved in the display cases on the walls. It is a very representative collection for the history of the Italian miniature of the fifteenth century. Beyond the Sienese artists, the most precious pages are those decorated by Girolamo da Cremona and Liberale da Verona.