Upon the entrance to the Library are the words of anathema uttered by the Pope upon any one who should dare to purloin books from the collection. There have been, however, many losses. The French plundered the Library, which, long before the invasion, was devastated by the fire of 1671, and from time to time the hand of the pilferer has been laid upon many of the volumes. From a nucleus of four thousand volumes, collected by Philip II. and placed in the Escorial, the Library grew in the number of its books, and in the costly manuscripts in Arabic and other Eastern tongues. At one period this was the most notable and valuable collection of Arab works in the whole of Europe. The gift of Don Diego de Mendoza’s private library further enriched the collection. Mendoza was Philip’s ambassador to Italy, and a man of wide culture and with a love of books. When the king inherited this splendid library, he satisfied all his ambassador’s creditors. Mendoza’s volumes were presented in 1576. They were bound in an unusual manner, one cover being red and the other black, and sometimes the leaf edges are decorated in two colours. Among other donors to the Library were Augustin, Archbishop of Tarragona, an eminent writer, Ponce de Léon, and Geronimo de Zurita, a historian. The Balearic Islands contributed about three hundred volumes, some of them being the writings of the remarkable Raymond Lully. From the Inquisition the Library received about one hundred and forty books. Authors of repute frequently presented their manuscripts to the great collection at the Escorial. In 1583 a Moorish interpreter, in the employment of Philip, was commissioned to buy all the Arab books that he could discover in Granada and Cordova. This bibliographer, Alonso de Castillo, appears to have devoted great labour to the extension of the Library and catalogue-making. About seventy manuscripts in Greek, Hebrew, and Arabic, were presented by Father Montano, who seems to have acted as librarian, though the first to hold that office was Father Juan de San Geronimo. Philip III. increased the Library by the addition of confiscated books seized from Don Ramuz del Prado; and in the reign of the same monarch, the collection of three thousand volumes belonging to the Emperor of Morocco was acquired. Anticipating the rule of our biggest public library, the British Museum, it was decreed that a copy of every book issued in Spain should be presented to the Escorial. Besides volumes of philosophy, history, theology, science, and poetry, there was a collection of church music in the Library, some of which was composed by the monks, del Valle, Torrijos, and Cordova. Many of the compositions of the renowned choir-master, Antonio Soler, are in the Library.