With Nerva and Trajan the happiest epoch of the principate set in. Nerva (96-98 A.D.) sprung from a line of distinguished jurists, was celebrated by Martial as the Tibullus of his time,[443] and is praised by the younger Pliny for the excellence of his light verses.[444] Trajan, his successor (98-117 A.D.), though a man of war, rather than a man of letters, wrote a history of the Dacian wars,[445] and possessed--as his letters to Pliny testify--a remarkable power of expressing himself tersely and clearly. He was, like Vespasian, a generous patron to rhetoric and education,[446] and the founder of the important library known as the _Bibliotheca Ulpia_.[447] But the great service which he and his predecessor rendered to literature was, as Pliny and Tacitus bear eloquent witness, the gift of freedom. This did more for prose than for poetry, save for one important fact--it was the means of enriching the world with the satires of Juvenal. If the quantity of the literature surviving from the principates of Nerva and Trajan is small, its quality is unmistakable. Pliny the younger, Tacitus, and Juvenal form a trio whose equal is to be found at no other period of the post-Augustan principate, while the letters of Pliny give proof of the existence of a highly cultivated society devoted to literature of all kinds. Poets were numerous even if they were not good. Few names, however, survive, and those have but the slightest interest for us. It will suffice to mention three of them: Passennus Paulus, Sentius Augurinus, and the younger Pliny. With the dramatic poets, Pomponius Bassulus and Vergilius Romanus, we have already dealt.[448] Pliny shall speak for himself and his friends. 'Passennus Paulus,' he writes,[449] 'a distinguished Roman knight of great learning, is a writer of elegies. This runs in the family; for he is a fellow townsman of Propertius and indeed counts him among his ancestors.' In a later letter[450] he speaks with solicitude of his failing health, and goes on to describe the characteristics of his work. 'In his verse he imitates the ancients, paraphrases them, and reproduces them, above all Propertius, from whom he traces his descent. He is a worthy scion of the house, and closely resembles his great ancestor in that sphere in which he of old excelled. If you read his elegies you will find them highly polished, possessed of great sensuous charm, and quite obviously written in the house of Propertius. He has lately betaken himself to lyric verse, and imitates Horace with the same skill with which he has imitated Propertius. Indeed, if kinship counts for anything in the world of letters, you would deem him Horace's kinsman as well.' Pliny concludes with a warm tribute to Passennus' character. The picture is a pleasant one, but it is startling and significant to find Pliny awarding such praise to one who was frankly imitative, if he was not actually a plagiarist.[451]