Hastings' Dictionary of the New Testament 
Titus Flauius Domitianus, second son of Titus Flauius Vespasianus (Emperor a.d. 69-79; see Vespasian) and his kinswoman Flauia Domitilla, arid brother of Titus Flauius Vespasianus (Emperor a.d. 79-81; see Titus), was Roman Emperor from a.d. 81 to 96. He was born on 24 October a.d. 51 in Rome, during the principate of Claudius, almost twelve years after his brother Titus. He lost his mother and only sister in early life, and when his father and brother entered on the Jewish War in a.d. 66, Domitian was scarcely fifteen years old. When his father was called to the Imperial throne on 1 July 69, his sons received corresponding honours, each being named Cœsar and princeps iuuentutis . Domitian had a narrow escape at the hands of the Vitellians, being compelled to leave the Capitol in the robes of a priest of Isis, which a freedman had procured for him. On his father’s accession Domitian received the praetorship, which he held from 1 January 70, but exercised for the most part by deputy. Following the fashion set by Augustus, he robbed L. Lamia aemilianus of his wife Domitia Longina, and, after living with her for some time unmarried, finally married her. It was unfortunate for his future career that his father and elder brother were absent for a lengthy period from Rome and Italy, being detained by the Jewish War. The sudden accession to power and influence of a youth of barely eighteen years of age ended, as might have been expected, in a disastrous perversion of character. The complaints against him served to hasten his father’s return. Before 21 June 70, Domitian and Mucianus, the most prominent supporter of the Flavian house, left Rome for the Gallo-German war. A change in the situation caused Domitian to return. He lived for a period in his Alban villa in retirement from public life. On the return of his father he received much distinction, but so far as direct government of the Empire was concerned he was kept in the background. He was, however, six times consul before he became Emperor. On the death of Vespasian (79) Titus became Emperor; Domitian, though openly spoken of as consors imperii , was wisely kept in an inferior position.
On the death of Titus through fever, Domitian became Emperor (13 September 81). Henceforth his title was Imperator Caesar Domitianus (Domitianus Caesar) Augustus. The title Germanicus was conferred upon him in 84, and he became censor perpetuus (after 5 Sept.) in 85. Certain of the important events of his reign may be enumerated. It was probably very soon after the death of Titus that the decree for the construction of the arch in his honour, still standing at the Summa Sacra Via , was passed. On it are the famous representations of the Golden Candlestick, etc. (see articleRome). His first year was also signalized by the victories of Cn. Iulius Agricola in Scotland and the establishment of fortified posts as far as the line of the Forth and Clyde. In 82 the rebuilding of the Temple of Jupiter on the Capitoline Hill, which had been destroyed by fire in 80, was completed. In the same year the roads in the Imperial provinces of Asia Minor were repaired, and Agricola carried out his fifth campaign, planning also an invasion of Ireland which never took place. In 83 an expedition to Germany took place as the result of which victories were gained over the Chatti. Territory was added to the Empire in the region of Taunus and Wetterau on the right bank of the Rhine, and secured by a fortified rampart ( limes ). This success brought the title Germanicus to Domitian on 3 September 84 (cf. Statius, Siluœ [ passim ] for the use of the name; passages in Klotz’s index, p. 187). About this time Domitian also allowed himself to be appointed consul for ten years, and received the censoria potestas for life, and other honours. The pay of the soldiers was increased by a third. In 83, on his sixth campaign, Agricola had been able, with the co-operation of his fleet, to extend his hold over our island. He marched as far north as Inchtuthill near Dunkeld, and made a lasting camp there. In 38 occurred the battle of Mons Graupius (locality uncertain), by which the Caledonians received a crushing blow. Agricola left Britain in a pacified state, when Domitian’s jealousy recalled him soon after this victory. In the period 85-87 Domitian led in person two expeditions against the Dacians, who had provoked war. They crossed the Danube and invaded the province of Mœsia. The governor of Mœsia, Oppius Sabinus, was defeated and killed. The Dacians thereupon ravaged the territory on the right bank of the Danube and destroyed towns and forts. About the end of January 86 Domitian himself took the field. Of the details of the war almost nothing is known. It appears that Domitian issued his commands for the most part from the Imperial camp in the province of Mœsia. The Decebalus was conquered, and Domitian took the credit of the victory to himself. He was back in Rome in the summer of 86, but the war was continued by Cornelius Fuscus, who appears to have suffered a heavy defeat.
About the same period the Romans were engaged in warfare against the Nasamones on the African coast, and against the Germans. It was in Domitian’s reign that the custom of buying off the opposition of Rome’s enemies began. During this period the Emperor became more and more a tyrant and less and less a constitutional prince. It is significant that he allowed himself to be called dominus ac deus (a.d. 85-86). Tyranny aroused the more republican of the senators, and many were condemned; a conspiracy against the Emperor was discovered and crushed. Probably about the end of 89 Domitian triumphed over the Dacians and the Germans, whose governor, L. Antonius Saturninus, sought to dethrone him. Domitian had taken part in both these wars himself. We learn also of an expedition against the Quadi, the Marcomani, and the Sarmatians, all of whom were allies of the Dacians. Domitian was recognized as victor, peace was made between the combatants, and large sums of money were sent by Domitian to the Decebalus. The year 89 was marked by further condemnations of distinguished persons and the confiscation of their property. Twenty years after Nero’s death (9 June 68) a false Nero appeared, and caused an uprising among the Parthians which it was extremely difficult to quell. It is not impossible that some reference to this occurrence is latent in Revelation 13:3. In the year 91 a Vestal virgin, charged with having broken her vow of chastity, was by the orders of the ‘censor’ Domitian subjected to the ancient penalty of being buried alive. In this year also was unveiled the great equestrian statue of Domitian in the Forum (celebrated by Statius in his Siluœ , i. 1), the base of which is still in position. In 92 (or, strictly, in the period Oct. 91 to Sept. 92) there was a good vine crop but a bad cereal crop. Domitian in consequence ordered that no new vineyards should be laid out in Italy and that the vines of the provinces should be reduced to one half their former number. This measure, intended to improve agriculture, was not carried out strictly. The provinces complained, among them Asia Minor. M. Salomon Reinach pointed out in 1901 (in RA [Note: A Revue Archéologique.], reprinted in Cultes, Mythes et Religions , ii.  356-380) that there is a reference to this edict latent, in the difficult passage Revelation 6:6 (see Sanday in Journal of Theological Studies viii. [1906-07] 488f.). In the same year Domitian conducted war against the Sarmatians with success. Next year (93) was marked by more condemnation of the nobility, and among others the great Agricola fell a victim. Now began the reign of terror which ended only with the death of Domitian. Among those who suffered were some of the noblest Romans, men and women, that ever lived.
It was in the year Oct. 93 to Sept. 94, according to the Chronicle of Eusebius, as translated by Jerome, that the Domitianic persecution of the Christians began, and that the Apostle John, being banished to the island ‘Pathmus,’ saw the Apocalypse (cf. other ancient references recorded in the introductions to the Commentaries by Swete, Bousset, and Hort, to which add pseudo-Augustine, Quœstiones Veteris et Novi Testamenti CXXVII , lxxvi. [lxxii.] 2: ‘ista Reuelatio eo tempore facta est, quo apostolus Iohannes in insula erat Pathmos, relegatus a Domitiano imperatore fidei causa’). For the difficulty in dating the Apocalypse see articleApocalypse. There must have been a fierce persecution of Christians in Domitian’s time, and the Apocalypse would seem to be the mirror of it. The Church always believed Domitian to have been the second great persecutor. The wonder is that the outbreak did not come earlier, in view of Domitian’s assumption of the titles ‘Lord and God’ referred to above. It has been usual to connect with this persecution the charge of ‘atheism’ (by which, of course, the Romans meant the worship of no god in visible form: they had long charged the Jews with the same [cf. Lucan, ii. 592-3: ‘dedita sacris incerti Iudaea dei’]) brought against two relations of the Emperor. These were Flauius Clemens, the consul of the year (95), first cousin of the Emperor, and his wife, Flauia Domitilla, niece of the Emperor. Clemens was beheaded, and Domitilla was banished to Pandateria. A grave in the catacombs near Rome belonged to the latter. Before the summer of this year 95 the Via Domitiana connecting Sinuessa and Puteoli was completed (celebrated by Statius, Siluae , iv. 3). This meant a saving of time for journeys from Rome to Naples and beyond (see articleRoads And Travel). In the year 96, on 18 Sept., the much-hated Emperor met his death at the hands of his friends, his freedman, and his wife.
Literature.-Among the ancient authorities, his beneficiaries Statius and Martial say all and more than all the good there is to be said of Domitian; the part of Tacitus’ Hist . dealing with him has perished; there are occasional references in contemporary authors, and there are the biography by Suetonius and parts of Dio Cassius, Orosius, etc. The best modern work is S. Gsell, Essai sar le règne de l’empereur Domitien , paris, 1894; there is an excellent résumé with references and literature in Weynand’s articleIn pauly-Wissowa, vi.  2541-2596; A. v. Domaszewski, Gesch. d. röm. Kaiser , Leipzig, 1909, vol. ii.; general histories of the Empire. On Domitian and Christianity see W. M. Ramsay, The Church in the Roman Empire , London, 1893, chs. xii. and xiii.
Cyclopedia of Biblical, Theological and Ecclesiastical Literature 
(Titus Flavius Domitianus ) Roman emperor, younger son of Vespasian and Domitilla was born October 24, A.D. 52, and succeeded his brother Titus as emperor September 13, A.D. 81. In the beginning of his reign he affected great zeal for the reformation of public morals, but his true character showed itself later in almost unexampled cruelties. In A.D. 95 a persecution of the Christians is recorded in the history of the Church, but it appears to have been directed particularly against the Jews, with whom the Christians were then confounded by the Romans. Suetonius (In Dornsitian. chapter 12) ascribes the proscriptions of the Jews, or those who lived after the manner of the Jews, and whom he styles as "improfessi," to the rapacity of Domitian. Eusebius (3:17) says that Domitian "was the second that raised a persecution against us, and established himself as successor of Nero in his hatred and hostility to God." The same writer (3:19, 20), following Hegesippus, tells of a summons of the grandchildren of Jude the apostle to appear before Domitian. He questioned them as to their birth, claims, property, etc. and when they answered that the kingdom of Christ, for which they looked, was purely spiritual, he dismissed them. The tyrant was not so lenient with his own relatives, Flavius Clemens and Domitilla, who were charged with "Atheism and Jewish manners," charges often brought against the Christians. Flavius was executed and Domitilla banished, A.D. 95. Domitian himself was assassinated (A.D. 96). A tradition (not now believed) speaks of St. John as having been tried before Domitian, and that, having been condemned to be plunged into a caldron of boiling oil, he came forth unhurt. See Milman, History of Christianity, book 2, chapter 4; Gibbon, Decline and Fall, chapter 16, and the article (See Persecution).
The Nuttall Encyclopedia 
Roman emperor, son of Vespasian, brother of Titus, whom he succeeded in 81, the last of the twelve Cæsars; exceeded the expectations of every one in the beginning of his reign, as he had given proof of a licentious and sanguinary character beforehand, but soon his conduct changed, and fulfilled the worst fears of his subjects; his vanity was wounded by the non-success of his arms, and his vengeful spirit showed itself in a wholesale murder of the citizens; many conspiracies were formed against his life, and he was at length murdered by an assassin, who had been hired by his courtiers and abetted by his wife Domitia, in 96.