[Sidenote: Later emperors.] Pertinax had literary tastes, but his brief reign gave him no opportunity to influence the course of the national literature, while his successor Didius Julianus, who bought the empire from the prætorian guards, found after sixty-six days of nominal power that his purchase brought him ruin and death. Septimius Severus (193-211 A. D.), although his native tongue was probably Punic, was well educated in Greek and Latin and wrote an autobiography, but there is no indication that he exercised any marked influence upon Roman literature. Among the later emperors were few whose literary interests were strong, and still fewer who appear as authors. In the third century Alexander Severus (222-235 A. D.) was seriously interested in Greek and Latin literature and encouraged literary production by all the means in his power; Gordian I (238 A. D.) wrote a metrical history of the Antonines in thirty books, besides various other works in prose and verse, but these are lost, and his brief reign did not enable him to give imperial encouragement to literature; the poems and speeches of Gallienus (260-268 A. D.) and the historical writings of Aurelian (270-275 A. D.) were of little importance. The Emperor Tacitus (275 A. D.) exerted himself to spread abroad the works of his ancestor the historian, and it may be due to him that those works are in part preserved. Those among the still later emperors who had literary interests made their influence felt rather upon Greek than Latin literature. [Sidenote: Suetonius.] The most important writer in the reign of Hadrian is Gaius Suetonius Tranquillus. He was born apparently between 70 and 75 A. D. He was a friend of the younger Pliny, who mentions him in his letters. Pliny obtained for him a military tribuneship, which he passed on to a relative. Pliny also assisted him in the purchase of a small estate and encouraged him to publish some of his writings. Under Hadrian he held a position as secretary, from which he was dismissed in 121 A. D. Of his later life nothing is known, but he probably devoted himself to his literary labors, and as his works were numerous, we may assume that he lived to an advanced age.