Emperor of the Romans; born 24 January, A. D. 76 at Rome; died 10 July, 138. He married his cousin and ward, Julia Sabina, grand-niece of Trajan. He reigned from 118 to 138, devoted himself to art and science, and possessed notable qualifications as a statesman and soldier. He abandoned Armenia, Mesopotamia, and Assyria, countries that his predecessor had hoped to acquire permanently by the conquest of the Parthians, and confined his efforts to developing the Province of Arabia. He strengthened his amicable relations with the Senate by various favours; he remitted arrears of taxes that had been owing to the treasury for fifteen years. The absolute power of the emperor reached limits never attained before. A conspiracy formed against Hadrian's life by distinguished officers during one of his campaigns in Mœsia was suppressed by the senators, and the four ringleaders were executed without the emperor's knowledge. In pursuance of his political, scientific, and military interests he travelled over the Roman provinces during his reign, first through those in the North and the North-West, then Spain and Mauretania, and finally the Orient and Greece, thereby assuring the loyalty of thirty legions and raising the discipline and warlike efficiency of the Roman army to a high standard, though his policy was far-sighted and peaceful. He was commemorated on the coinage as the restorer of the provinces. By protecting the boundaries in the valley of the Lower Danube, and by building many fortified places he encouraged the settlement of the province of Dacia by Roman colonists. In Germany he completed the palisaded ditch between the Rhine and the Danube (limes Hadriani). In Britain the legions constructed a fortified wall extending from the mouth of the River Tyne to the Solway Firth (vallum Hadriani) to protect the Roman boundaries from the inroads of the Picts. This has been partially preserved. He desisted from any attempt to subjugate the northern part of the island. Numerous fortresses and military roads were built in Africa and on the Black Sea. He built up the old Thracian colony Uscudama into the flourishing city of Adrianople. A description of the Pontic coasts was written at Hadrian's request by his legate, the historian Flavius Arrianus of Nicomedia, in his "Periplus". Although on his return he had lost some of his popularity at Rome, he made a second tour abroad for several years in 129, and conferred such an abundance of benefits and gifts, particularly on Greece and Athens, that, according to his biographer Spartianus, this city, where a new section called Hadrian's quarter was built at the south-east of the old town, again became the centre of Hellenic culture. He completed the Olympieum that Pisistratus had begun, the largest temple in the Græco-Roman world.
The Greeks set up Hadrian's statue in the temple at Olympia and built the Panhellenium in the new town in honour of Zeus Panhellenius. In the provinces of Asia Hadrian encouraged and aided the construction of aqueducts, bridges, roads, and temples, and the restoration of ruined cities. By this means he sought to relieve economic distress and at the same time to promote his domestic policy. During an inundation of the Nile, while he was travelling through Egypt, his favourite, the beautiful young Antinous, a native of Bithynia, was drowned, in the year 130. The emperor caused him to be deified. In order to prevent the recurrence of insurrections by the Jews, who in their religious schools were cherishing hopes of reviving a Jewish kingdom under the Messias, the emperor ordered the Roman troops in Jerusalem to raze the ruins left standing in that ancient city and to set up a military colony, Ælia Capitolina. It was his wish to eradicate Judaism as such. The Jews revolted in 132 under Simon, whom they called Bar-Cocheba. (Son of the Stars). Inside of three years Sextus Julius Severus put down the rising amid terrible destruction and bloodshed. The Jews were forbidden to set foot within the old city. In the year 134 Hadrian returned to Italy. He built a temple to Trajan in Rome, a colossal double temple to Venus and Roma, and the gigantic mausoleum on the right bank of the Tiber, which constitutes the kernel of the castle of Sant' Angelo. At his villa near Tivoli he copied the monuments and landscapes that had made the strongest impressions on him during his travels. In order to unify jurisprudence throughout the entire empire, he ordered the prætor Salvius Julianus to revise and codify systematically the prætorian edicts and the annual supplementary edicts. In the year 131 this "perpetual edict" (edictum perpetuum) obtained force of law by virtue of a decree of the senate; the same force was given to the opinions of the jurisconsults in all points wherein they were agreed among themselves, in order, that the system of the law might continue to develop. He bestowed the highest administrative offices on men of knightly rank, instead of on freedmen as heretofore, and regulated the succession of these officers. During his absence from Rome he had created an efficient, salaried council, clothed with statutory authority, which was confirmed by the senate, and which had the decision of all current important affairs in the administration of the empire. According to Hadrian's wishes, the Christians were to be punished only for such offences as came under the common law. Although there was no outspoken statutory toleration of them, they were not persecuted on account of their religion. With the sanction of the senate, he adopted L. Ceionius Commodus Verus and designated him as his successor by having the title of Cæsar conferred on him in 136. Because his brother-in-law, L. Julius Ursus Servianus, cherished hopes of the succession for his own youthful grandson, Fuscus Salinator, Hadrian had them both put to death. After the death of Verus (1 January, 138) he adopted the admirable Aurelius Antoninus, who was fifty-two years old, appointed him co-ruler with himself, and prevailed upon him to adopt L. Verus, the son of his own first adopted son. Hadrian died of dropsy on 16 July, 138.
GREGOROVIUS, Der Kaiser Hadrian, Gemälde der röm.-hellen. Welt (3 vols. Stuttgart, 1884); DÜRR, Die Reisen Kaiser Hadrians (Vienna, 1881); HILZIG, Die Stellung Kaiser Hadrians in der röm. Rechtsgeschichte (Zurich, 1892); SCHILLER, Römische Kaiserzeit, (2 vols. Gotha, 1883).