Trajan. MARCUS ULPIUS TRAJANUS, Roman emperor, was born at Italica (near Seville) about 56. He was descended from a family which was probably of Roman origin, was early trained to arms, and gaining distinction in the Parthian and German campaigns was made prætor and consul (91), and was adopted (97) by Nerva as his colleague and successor. He became sole ruler in the following year. In 101 Rome for the first time beheld its emperor leading forth his legions in person on a career of conquest, when Trajan set out on his first campaign against the Dacians. The struggle was long and fierce; the emperor's opponents were valiant warriors, and headed by an able leader, their monarch, Decebalus; but the Romans at last gained a decisive superiority, and in a subsequent campaign (105) completely subdued their opponents, whose country thenceforth became the Roman province of Dacia, and was secured by partial colonisation. This conquest was celebrated on Trajan's return to Rome by a triumph, and by games on a most extensive scale. In 113 the emperor left Italy for his great expedition in the East, directed mainly against the Parthians. Landing in Syria he made Armenia and Mesopotamia into Roman provinces, and advanced to Ctesiphon on the Tigris, meeting however with actual defeat at Ctesiphon and Hatra. Meanwhile the Jews rose in Cyprus and Cyrene and made fearful massacres; and other enemies took advantage of the emperor's absence in the far east. Trajan took ship for Italy, already in failing health, and was overtaken by death at Selinus in Cilicia, August 117. Though most of Trajan's reign was spent in the field, the internal administration was carefully and excellently guided; the administration of justice was vigorous and impartial; that of finance was equally admirable; informers (delatores) were severely punished, and peculating governors of provinces rigorously prosecuted. The improvement and beautifying of Rome was carried on; the empire was traversed in all directions by new military routes, canals and bridges were constructed, new towns built, the Via Appia was restored, the Pontine Marshes partially drained, the magnificent 'Forum Trajani' erected, and the harbour of Centum Cellæ (Civita Vecchia) constructed. His mildness and moderation were proverbial; and though he persecuted the Christians, it was because he regarded the new religion as distinctly subversive of the state. His famous letter to Pliny (q.v.), then legate in Bithynia and Pontus, shows his character in this regard, and his sincere desire for the comfort and happiness of his subjects is reflected in the customary wish formally uttered on the occasion of an emperor's accession—that he might be 'happier than Augustus, better than Trajan' (Augusto felicior, Trajano melior). A popular mediæval legend even described him as saved by the prayers of Pope Gregory I. from the pains of hell. Trajan's Column is described at ROME, Vol. VIII. p. 782. Trajan's Wall is the name given to an old Roman earthwork in the Dobrudja, running from the Danube above Czeranovoda to Knstendji on the Black Sea; it is an earthen wall, 8 to 15 feet high, and was deftly built against the Russians in 1854.
There are works on Trajan by Francke (2d ed. 1840), Dierauer (1868), and De la Berge (1877). See also Merivale, and H. Schiller's Gesch. der Röm. Kaiserzeit (Gotha, 1883).