The honor of having first established these valuable institutions is ascribed by the elder Pliny to Asinius Pollio, who erected a public library in the Court of Liberty, on the Aventine Hill. The credit which he gained thereby was so great, that the emperors became ambitious to illustrate their reigns by the foundation of libraries, many of which they called after their own names. Augustus was himself an author, and in one of those sumptuous buildings called _Thermoe_, ornamented with porticoes, galleries, and statues, with shady walks and refreshing baths, he testified his love of literature by adding a magnificent library, which he fondly called by the name of his sister Octavia. The Palatine Library, formed by the same emperor, in the Temple of Apollo, became the haunt of the poets, as Horace, Juvenal, and Perseus have commemorated. There were deposited the corrected books of the Sibyls; and from two ancient inscriptions, quoted by Lipsius and Pitiscus, it would seem that it consisted of two distinct collections--one Greek, and the other Latin. This library having survived the various revolutions of the Roman Empire, existed until the time of Gregory the Great, whose mistaken zeal led him to order all the writings of the ancients to be destroyed. The successors of Augustus, though they did not equally encourage learning, were not altogether neglectful of its interests. Suetonius informs us that Tiberius founded a library in the new Temple of Apollo; and we learn from some incidental notices that he instituted another, called the Tiberian, in his own house, consisting chiefly of works relating to the empire and the acts of its sovereigns. Vespasian, following the example of his predecessors, established a library in the Temple of Peace, which he erected after the burning of the city by order of Nero; and even Domitian, in the commencement of his reign, restored at great expense the libraries which had been destroyed by the conflagration, collecting copies of books from every quarter, and sending persons to Alexandria to transcribe volumes in that celebrated collection, or to correct copies which had been made elsewhere. But the most magnificent of all the libraries founded by the sovereigns of imperial Rome was that of the Emperor Ulpius Trajanus, from whom it was denominated the Ulpian Library. It was erected in Trajan's Forum, but afterwards removed to the Viminal Hill, to ornament the baths of Diocletian. In this library were deposited the elephantine books, written upon tablets of ivory, wherein were recorded the transactions of the emperors, the proceedings of the senate and Roman magistrates, and the affairs of the provinces. It has been conjectured that the Ulpian Library consisted of both Greek and Latin works; and some authors affirm, that Trajan commanded that all the books found in the cities he had conquered should be immediately conveyed to Rome, in order to increase his collection.